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Ask Dr. Universe Biology
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May I ask how fish breathe? – Nghi, 11, Vietnam

Dear Nghi,

When you and I take a deep breath, we pull air into our lungs. That’s because humans and cats are mammals. But fish aren’t mammals. They usually don’t breathe air. They usually don’t have lungs.

That’s what I found out from my friend Michael Berger. He’s a biologist at Washington State University.

He told me that you can actually see a fish breathe water. Its face gets bigger when it takes in a big gulp of water. Just like when you take a big bite of food.

When you look at a fish, you can usually see the gill openings—called gill slits. … » More …

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How many species do we have on Earth? – Varish, 10, Michigan

Dear Varish,

If we count all the species that humans have described so far, it’s about 2 million. New species get added all the time—about 15,000 of them every year.

But we have no idea how many species we’ve never met. Scientists think there could be 5 million species out there. Or maybe billions.

We’ll only know for sure when we describe all those organisms.

I asked my friend Rich Zack what that means. He’s an insect scientist at Washington State University.

He told me how we identify and name a new species.

Imagine we’re in my backyard collecting insects together. We see a … » More …

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Why do scientists use Latin when they name organisms? – Arielle, New York

Dear Arielle,

Language changes all the time. Words get new meanings. New words get made up.

I talked about it with my friend Rich Zack. He’s an insect scientist at Washington State University. He does taxonomy. That’s the science of naming and classifying living things.

The way language changes is amazing—and skibidi. It’s neat that language morphs as we use it. But that can limit how well we understand each other. Some readers might see “skibidi” and think I passed out and hit random keys.

That’s the main reason scientists use Latin or ancient Greek to name things. They’re dead languages. Nobody uses … » More …

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What is the likelihood that all your lysosomes could burst at the same time? Would you spontaneously dissolve? – Annika, 12, Pennsylvania

Dear Annika,

I’d love to read a creepy science fiction story where people dissolve.

I asked my friend Anders Omsland if that could happen. He’s a biomedical researcher at Washington State University.

He told me a lysosome is a specialized compartment in a cell. It’s like a little sack of digestive enzymes. Those are proteins that break stuff down. Our cells use lysosomes to help destroy germs or recycle old or messed up cell parts.

Lysosomes are basically the cell’s trash and recycling centers.

“I don’t think it’s possible for lysosomes to all pop at the same time,” Omsland said. “They don’t really explode … » More …

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Why do we lose our hearing when we get older? – David, 10, Wisconsin

Dear David,

I love visiting with my grandcat. But sometimes I have to talk loudly so she can hear me.

I asked my friend Christine Portfors why that is. She’s a biologist at Washington State University.

She told me it’s all about the hair cells inside our ears.

They aren’t really hairs. They’re sensory cells. Hair cells have tiny, bristle-like tufts that stick out—called cilia—that look a little bit like hairs.

Those hair cells are why we can hear.

First, sounds funnel into our ears. They bonk into the ear drum and make it vibrate. Then, three itty, bitty bones make those … » More …

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How do bugs cling onto things without falling off? – Carmen, 7, Washington state

Dear Carmen,

Right now, there’s a fly walking on the window in my office. I asked my friend Rich Zack how it does that. He’s an insect scientist at Washington State University.

It turns out my window isn’t as smooth as it looks. If we zoomed in on the glass, we’d see bumps and dips. It’s kind of like a rock face or a climbing wall.

“Surfaces look pretty smooth,” Zack said. “But if you get really, really close, you see there are all kinds of little indentations and crevasses. Even a pane of glass is not perfectly smooth. It’s got little nicks and … » More …

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Why do people have allergies? – Hailey, 11, Washington state

Dear Hailey,

Under my lab coat, I have a splendid fur coat. That can be a problem when I work with someone who’s allergic to cats.

I asked my friend Ed Johnson about it. He teaches classes about the human body at Washington State University.

He told me that allergies happen when your immune system overreacts to a normal thing it perceives as a threat to your body. That thing can be pollen, dust, food, medicine, insect venom or something else. It can be bits of fur and shed skin called cat dander.

“The immune system evolved to protect the body,” Johnson said. … » More …

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Do plants have feelings or consciousness? – Ella, 10, Wisconsin

Dear Ella,

I love plants. But when I hug a tree, does it love me back? Does it think about anything at all?

I talked about your question with my friend Michael Knoblauch. He’s a plant scientist at Washington State University.

He told me that whether or not plants have feelings or conscious thought is an open question. Right now, most scientists think it’s unlikely.

Animals like us feel and think—and we’re aware that we feel and think. Scientists believe that has to do with how our brains evolved.

Plants don’t have brains and nervous systems like ours. They can send and receive … » More …

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What is the largest insect in the world? – David, 10, Wisconsin

Dear David,

I like big bugs. I cannot lie.

But which insect is the biggest? I asked my friend Rich Zack. He’s an insect scientist at Washington State University.

He told me the answer depends on how you define big.

One way is how much matter makes up an insect’s body. The insects with the most body mass are giant beetles. These include titan beetles, Goliath beetles, rhinoceros beetles and elephant beetles. They can be the size of a mouse.

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Why do bees make honey? – Gabby, 9, Kansas

Dear Gabby,

As a science cat, I don’t stir honey into my tea or drizzle it on my biscuits. I don’t have taste receptors for sweet things. Honey doesn’t have a taste to me.

But my human friends gobble up the honey made by the Washington State University bees. I asked my friend Rae Olsson why bees make that sticky stuff in the first place. Olsson is an insect scientist.

It turns out honey is the way honey bees store food for the winter.

“Just like we store food in our refrigerators and pantries, bees turn nectar from flowers into honey, so it doesn’t spoil,” Olsson said.

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How do we get muscles? – Jalane, 10, Ohio

Dear Jalane,

I’ve always been a bookish cat. I spend most of my time in the lab rather than running, prowling and pouncing like most felines.

But I still have super strong muscles. They’re way bigger than when I was a kitten.

I asked my friend Edward Johnson how I got so buff. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

He told me that muscles are made of muscle cells. They’re also called muscle fibers or myocytes.

We usually think cells are way too small to see with our eyes. But muscle cells can be some of the longest cells in your body. They’re shaped like long tubes or hot dogs. Each muscle cell is as long as the muscle it’s part of. So a muscle cell in a grownup’s thigh muscle could be 14 inches long!

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Do butterflies have meat in their bodies? – Fiona, 4, Iowa

Dear Fiona,

When I was a kitten, I loved chasing butterflies. It’s fun to run after them as they flit and flutter.

But I didn’t eat them.

I asked my friend Rich Zack if that was an oversight. He’s an insect scientist at Washington State University.

He told me that insects are animals with muscles just like other animals that people eat—like cows and chickens.

“Insect muscle tissue is almost exactly the same as mammalian muscle tissue,” Zack said. “So, if there were a way to get that muscle tissue and process it, you could eat an insect steak or an insect hamburger.”

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Why do birds migrate? – Lebron, 9, Virginia

Dear Lebron,

One of my favorite sights is when geese fly south in a “V” formation. As a cat, I’m pretty independent. So, I think it’s amazing to see birds fly together like that.

I talked about why birds migrate with my friend Heather Watts. She’s a biologist at Washington State University. She studies important animal behaviors like migration.

She told me that migration is a movement animals make that’s outside their normal day-to-day pattern. It’s usually a temporary movement. They leave for a little while and then come back.

Lots of animals migrate, but we usually think of birds doing it. The big reason birds migrate is to find things they need like food and places to nest.

“We think that, in most cases, birds are migrating to make use of resources—and that's usually food that's available only at some times of year,” Watts said.

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What is the human brain made out of? – Trevor, 9, Illinois

Dear Trevor,

Everything we do and think is thanks to the 3-pound organ tucked into our skulls. But what is it made of?

I asked my friend Samantha Gizerian. She’s a brain scientist at Washington State University.

She told me the brain is surprisingly soft and mushy.

“We think about our other organs and tissues, and they’re squishy in a very solid way,” Gizerian said. “Like when you go to the grocery store and get a carton of meat. You can squish on the steak, right? Our other organs are mostly like that as well. But the brain is very, very delicate.”

She told me it’s more like the ground up burger people use to make meatballs. Or like soft tofu or a Jello square.

The brain is extra soft because it’s about 60% fat.

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Why do bugs fly in a big group? What are they doing? – Hudson, 7, Washington state

Dear Hudson,

The other day I walked into a cloud of gnats. I love insects, but it was unpleasant to have all those critters fly into my whiskers.

I asked my friend Rich Zack what they were doing. He’s an insect scientist at Washington State University.

He told me that most insects are individualistic. They don’t usually fly together in groups—unless they need to mate or travel. Then, some insects form a group called a swarm.

“The purpose of the adult insect is to mate,” Zack said. “They have short lives—so short that a lot of them don’t even feed as adults. So, the mating period is very important to them.”

That’s what my gnats were doing.

The conditions outside were just right, so a bunch of male gnats showed up in the same place. When female gnats got there, it was easy for them to find a mate—because everybody was together.

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Why did people stop exploring the ocean? I heard they only explored 5% of it. – Dakota, 11, New Mexico

Dear Dakota,

When I think about exploring the ocean, I think about the discovery of giant tube worms. They live in super- hot, mineral-rich water deep in the ocean. They don’t do normal things like eat or poop—but they can live for 300 years or longer. Scientists were shocked when they found them—and there’s probably much more to find.

[caption id="attachment_7794" align="alignnone" width="396"] These are tube worms that live by underwater volcanoes near the Galapagos Islands. The feathery red part is like a gill. It's filled with blood. It absorbs chemicals from the water and the volcano vent. Image: NOAA[/caption]

I talked about ocean exploration with my friend Gretchen Rollwagen-Bollens. She’s a biological oceanographer and plankton ecologist at Washington State University.

She told me that you’re right that we’ve only explored about 5% of the ocean. But it isn’t because we stopped trying. The ocean is just massive.

The ocean contains more than 321 million cubic miles of water. To imagine that, think of something that’s about a mile away from you. You might need to use a map app. Or ask a grownup for a landmark.

Now picture a giant 3D cube that same distance on each side. It’s 1 mile long, 1 mile wide and 1 mile deep. You would need 321 million of those to equal the ocean. Or think of a 1-gallon milk jug. All the water in the ocean would fill about 325 quintillion jugs.

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Why do birds sing in the morning? – Alexandria, 9, Wisconsin

Dear Alexandria,

I usually write answers to kids’ science questions early in the morning. I like how it’s so quiet—except for my bird neighbors singing and singing.

I asked my friend Jennifer Phillips what’s going on. She’s a bird scientist at Washington State University.

She told me birds sing in the morning to tell other birds that their territory still belongs to them.

“The morning time is usually a little bit more calm, especially in windy areas,” Phillips said. “So, it's a good time to broadcast your song and for that song to potentially travel a little farther.”

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Why do we need to hydrate? – Victor, 9, Ohio

Dear Victor,

Is there anything better than lapping up cool water on a hot day?

I talked about why we need to hydrate with my friend Ed Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

It turns out that up to 60% of an adult human’s body is water. A kid’s body contains even more water than a grown up. When you were a baby, you were about 78% water.

Humans use that water for all kinds of things. It keeps you cool when you sweat. It removes waste when you pee. It moves important stuff around inside your body. It even cushions your brain and spinal cord.

But staying hydrated is really about your cells.

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What is the most dangerous insect in the world? – Juan Simon, 9, Chile

Dear Juan Simon,

The deadliest animal on Earth isn’t a shark or a bear. It’s an insect. Mosquitoes kill way more people than any other animal.

I talked about it with Jeb Owen. He’s an insect scientist at Washington State University.

He told me mosquitoes are dangerous because of the way they sometimes eat.

“Through blood feeding, mosquitoes can transmit pathogens that make people and animals sick,” Owen said.

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Why do we have nose hairs? – James and Zion, 10, Virginia

Dear James and Zion,

Despite being a curious science cat, I must confess I haven’t spent much time looking up human noses. But I have noticed that human nostrils can be a bit…furry.

I talked about what’s inside your nose with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

He told me that nose hairs only grow in your nose’s vestibule. That’s the inside of the part of your nostrils that you can flare out. The nose hair’s job is to filter the air you breathe in through your nose.

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How are plants considered living if they don't have a heart or brain? – Lily, Pennsylvania

Dear Lily,

You and I are both animals with backbones, so we have lots in common. Our ways of being alive look similar. We have hearts to pump blood. We have brains that help us think and communicate.

But plants don’t have the same body systems we do.

I talked about your question with my friend Michael Knoblauch. He’s a plant scientist at Washington State University.

He told me plants are seriously good at being alive. In fact, 80% of all the living things on Earth are plants.

“Go out in the forest and look around,” Knoblauch said. “You might see birds and … » More …

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What would happen to female honey bees if male bees didn't exist? – Emmie, 12, Arizona

Dear Emmie,

When I want something sweet, I pull out a jar of honey made by my bee friends at Washington State University. I talked about your question with one of the insect scientists there, Rae Olsson.

They told me a honey bee colony includes one female queen, many female workers and, depending on the time of year, some male drones.

Workers have lots of jobs. They gather nectar and pollen. They take care of each other, the queen and the baby bees.

A drone’s only job is to mate with a queen from another colony.

The queen’s only job is to … » More …

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Why do plants need water? – Emma, 9, New York

Dear Emma,

When I’m thirsty, I pick up a glass of water with my paws and drink it—just like you do. But plants don’t have paws or mouths, so how (and why) do they drink it?

To find the answer, I talked with my friend Helmut Kirchhoff. He’s a scientist at Washington State University. He studies plants and biochemistry.

He told me plants need water inside their cells. Water makes plant cells strong and flexible. It also dissolves stuff. That makes it possible for chemical reactions to happen inside plant cells—like the reactions a plant uses to make energy during photosynthesis. Plants also need water to move around nutrients and other molecules required for life.

“Water is essential for life, but plants must move nutrients from the soil to the leaves,” Kirchhoff said. “So, they have this very nice transport system called xylem. Xylem is an ancient Greek word that means wood. It works like a straw to move water and nutrients from the roots to the leaves.”

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Where do frogs go in the winter? – Landon, 13, Washington

Dear Landon,

When the cold weather comes, I bundle up in a sweater and explore the snow.

But my frog friends are never around then. In fact, I’ve never seen a frog in a sweater.

I asked my friend Erica Crespi why that is. She’s a biologist at Washington State University. She studies frogs and other amphibians.

She told me frogs are different from you and me. We’re warm-blooded. Our bodies use energy to make heat. When it’s cold outside, it’s still warm inside our bodies. We just put on warm clothes to keep our heat from escaping.

But frogs are cold-blooded. They don’t spend a lot of energy making heat. So, when it’s cold outside, it’s cold inside a frog’s body, too. That could be bad news during a winter freeze.

Crespi told me that’s why most frogs living in places with cold winters find a slightly warmer place to hunker down.

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How are the insides of an insect different from a human? – Landon, 11, California

Dear Landon,

I love taking selfies with my insect friends. They’re so tiny and look so different from a big cat like me.

But my friend Rich Zack told me that insects and humans have lots in common. He’s an insect scientist at Washington State University.

“There are body systems that every animal needs,” Zack said. “Insects are relatively advanced animals, so they do a lot of things like humans do.”

That means many of an insect’s body systems are like yours. But there are three body systems that are super different for insects. Those are the skeletal, circulatory and respiratory systems.

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Why are dolphins mammals and not fish? – Evie, 9, Washington

Dear Evie,

As fellow mammals, you and I have a lot in common. It’s easy to see our similarities because humans and cats spend lots of time together. We may even be roommates or family.

But humans and cats don’t usually have dolphin besties. It’s harder to see what we have in common when our bodies and lives are so different.

To better understand mammal life, I talked with my friend Kevin Turner. He teaches marine biology at Washington State University.

“The name mammal comes from the presence of mammary glands,” Turner said. “So, the major characteristic of mammals is that we have mammary glands to produce milk for our offspring.”

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Why do marine mammals have horizontal tails, but fish have vertical tails? – Peyton, 11, Washington

Dear Peyton,

When you think about a whale, you probably picture an enormous sea creature without legs. But what if I told you the first whale had four legs and could walk on land?

I talked about whales and other marine mammals with my friend Kevin Turner. He teaches marine biology at Washington State University.

He told me marine mammals have horizontal tails because they flex their bodies up and down to move. Fish flex their bodies side to side. Scientists think it has to do with the way different animals evolved.

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How do animals breathe underwater? – Kinsley, 9, North Carolina

Dear Kinsley,

Have you ever seen a diving beetle? They’re one of my favorite animals. They live underwater and breathe air from a bubble attached to their butts.

I talked about all the ways animals breathe underwater with my friend Wes Dowd. He’s a marine biologist and animal physiologist. He studies how living things interact with the world around them.

Animals need oxygen. For air-breathers like us, oxygen is mixed into the air. For water-breathers, oxygen is mixed into the water. To get oxygen into our bodies, we all need organs and tissues made of very thin material with lots of surface area. That means lots of places that touch the air or water where oxygen can pass through. Like inside lungs or gills. Or the skin of frogs, toads, newts and salamanders that can live on land or underwater.

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How can we help bees survive harsh winters? – Carla, 10, Texas

Dear Carla,

I keep mason bees. They sleep in cardboard tubes all winter long. I worry about my little bees until I see them chew out of their nesting tubes in the spring.

I talked about how mason bees and all kinds of bees survive winter with my friend Brandon Hopkins. He’s an insect scientist at Washington State University. He manages the honey bees on campus.

The honey bees we see in North America today first arrived with Europeans in the 1600s. We love honey bees because they pollinate our crops and make delicious honey. But there are lots of bees that have always lived here—like bumble bees, squash bees and mason bees. Those are native bees.

Most native bees survive the cold by overwintering in the nests where they were born. That could be tucked into the soil or leafy debris. It could be nestled inside hollow plant stems, holes in wood or tubes like my mason bees. Some native bees like bumble bees live in colonies. Only the queen survives the winter. She digs into the earth or finds a hollow tree and hibernates there.

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Why do birds circle when they find food instead of just going and eating it? – Eden, 7, Michigan

Dear Eden,

I live close to a natural area with lots of birds of prey like hawks and eagles. I love to watch them sit in ginormous nests on top of electrical poles. Or swooping around in big circles while they search for a meal.

I talked about why they circle with my friend Jennifer Phillips. She’s a wildlife ecologist at Washington State University. She studies the relationship between birds and the environment.

She told me that birds of prey fly in a circle because they’re riding warm air currents called thermal updrafts or thermals. As the sun heats the Earth, some pockets of air get hotter than others. That warmer air rises. Birds can hop on those warm, rising thermals and ride them. That saves energy.

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What and where is the rarest plant in the world? – Thomas, 7, Virginia

Dear Thomas,

Every few years, a smell like a rotting corpse wafts around a stairwell at Washington State University Vancouver. But it’s not really a dead body. It’s the bloom of the corpse flower plant.

There are fewer than 1,000 corpse flower plants left in the wild. It’s one of the rarest plants in the world.

But the list of rare plants is massive. If you look at all the plants we know about in the world, there are about 435,000 different kinds of plants—and many more we don’t know about. Some scientists say that more one-third of all plants are “exceedingly rare.”

I asked my friend Dawn Freeman what makes a plant rare. She’s responsible for the WSU corpse flower.

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How does your body heal cuts and scrapes? – Liam, 11, California

Dear Liam,

Did you know your skin is the largest organ in your body? The average 5th grader has more than 6 pounds of skin. Whoa.

Skin protects the inside of your body from the dirty outside world. It keeps your insides from drying out and ensures a steady body temperature. It lets you feel things you touch.

Your skin also has the incredible ability to heal itself. I talked about that with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

“Skin is the point of contact between you and everything in your environment,” Johnson said. “So, it's evolved the ability to regenerate.”

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Are mermaids real? Is there a species that contains DNA that’s half human and half fish? – Maite, 12, Texas

Dear Maite,

People have thought about mermaids for a long time. Ancient people even drew humans with fish tails on cave walls. So, did they really see mermaids or were they drawing from imagination?

The marine experts from the National Oceanic and Atmospheric Administration (NOAA) say that no mermaids have ever been found in the ocean.

But we’ve fully mapped only about one-quarter of the ocean floor. There are probably between 700,000 and one million different kinds of plants and animals in the ocean. At least two-thirds of those are still unknown to us.

Does that mean mermaids could be swimming around in parts of the ocean we haven’t explored? Maybe. But our best guess is that people mistook other sea animals for mermaids—like manatees and their relatives.

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What is mutualism in nature? – Luke and Wade, 10, Maryland

Dear Luke and Wade,

When I get the same question from different kids, I know it’s a good one.

So, I talked about your question with my friend Angeliqua Montoya. She’s a graduate student at Washington State University. She works on a mutualism between pea plants and bacteria.

“I study ecology, which is looking at interactions between different species,” she said. “Mutualisms are interactions where both species benefit.”

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How do fish hear? — Lamarcus, 8, Ohio

Dear Lamarcus,

My goldfish roommate hates when people tap on his tank. The tapping sound he hears in the water is loud and scary.

I talked with my friend Rikeem Sholes about how fish hear. He’s a fish scientist. He studies salmon hearing at Washington State University.

He told me that a fish’s hearing system includes sensory cells in the inner ear and in a line along the outside of the fish’s body and head. Some fish also use their swim bladder to have super hearing.

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Why do dolphins and beluga whales have echolocation and what is it? – Carolyn Grace, 8, Virginia

Dear Carolyn Grace,

Toothed whales—like dolphins and belugas—might live in the ocean, but they have some big things in common with cave-dwelling bats. They’re all mammals that live in dark places and use echolocation.

That’s why I talked about your question with my friend Christine Portfors. She’s a biologist at Washington State University. Her lab keeps a colony of bats.

Many bats sleep in caves and zoom around at night. Their world is dark, so they use sounds and their echoes to perceive the world around them, which is called echolocation. Toothed whales live in dark oceans or murky rivers and lakes. That’s why they use echolocation, too.

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What makes fireflies light up at night? – Asher, 7, Maryland

Dear Asher,

When I was a kitten, there were tons of fireflies in my grandparents’ yard. My litter mates and I loved to gently catch them and let them go.

I talked with my friend Richard Zack about how and why fireflies light up. He’s an insect scientist at Washington State University.

Those glowing insects are a kind of beetle. But we call them fireflies or lightning bugs. Their glow is a form of bioluminescence. That’s when a chemical reaction inside a living thing makes it light up.

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What are butterfly cocoons made of? — Anabelle, 8, Massachusetts

Dear Anabelle,

When I was a kit, I looked a lot like the adult cat I would become—even though I was smaller and fluffier. But wiggly caterpillars don’t look like butterflies at all.

I talked about this with my friend Allan Felsot. He’s an insect scientist at Washington State University.

He told me cocoons are mostly silk. But they’re usually made by moths. A butterfly “cocoon” isn’t really a cocoon at all. It’s called a chrysalis.

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How does hair grow? – Aidric, 9, Ohio

Dear Aidric,

My whole body is covered in thick, glossy cat fur. Humans look mostly furless. But people grow hair on every part of their bodies except the palms of the hands and soles of the feet. Most human hair is just super fine and hard to see.

That’s what my friend Edward Johnson told me. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

He also told me hair grows from follicles. Those are special organs in the top layer of the skin. Everything you need to grow hair is inside the follicle.

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Why do all insects have six legs? – Charlie, 10, Ohio

Dear Charlie,

There are about 40 kinds of cats out there—like me. There’s only one kind of human on Earth now. But there are more than a million kinds of insects. That’s just the insect species we know about.

Every single one of those insects has six legs.

I talked about why that is with my friend Allan Felsot. He’s an insect scientist at Washington State University.

He told me there must be some evolutionary reason insects have six legs—like better stability when walking.

“In biology, every ‘why’ question has the same answer,” Felsot said. “Things are the way they are because of adaptations that have allowed organisms to live longer.”

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Why do crickets make sound? – Carola, 7, Virginia

Dear Carola,

Have you ever read the book “The Very Quiet Cricket?” It’s about a young cricket who can’t chirp until he grows up.

My friend Rich Zack reminded me of that book when we talked about your question. He’s an insect scientist at Washington State University.

He told me only adult male crickets make sound. Sometimes they chirp to defend their territories. It’s how they tell other male crickets to stay away.

But the main reason they chirp is to find a mate. Cricket chirps are mating songs. That song will be different for different kinds of crickets—and the song changes when the female cricket shows up.

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I want to know how snake venom in the antidote makes sense? – Raagini, 10, New York

Dear Raagini,

One of my roommates is a corn snake named Buddy. He’s not venomous. But he’s a very private individual and really likes his space.

Buddy and I talked about your question with my friend Blair Perry. He’s a biologist at Washington State University. He’s an expert on snakes and venom.

Perry told me antivenom doesn’t contain actual snake venom. It’s made with antibodies to snake venom.

Antibodies are proteins. They’re part of your immune system. They travel in your blood to fight germs or dangerous molecules—like those in venom—that could hurt you. Sometimes we get vaccines to boost our antibodies so they’re ready when something harmful shows up.

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Do your eyeballs grow? – Ashlynn, 8, Utah

Dear Ashlynn,

I was the cutest kitten. I bet you were an adorable baby, too. Like me, you probably had a big, round head with chubby cheeks and huge eyes.

The fact babies have big eyes made some people think babies are born with adult-sized eyeballs. I talked about this with my friend Edward Johnson. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

“It’s a very good question because there’s a lot of misinformation about it,” Johnson said. “Eyeballs do grow—but not very much compared with other parts of the body.”

He told me to … » More …

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Do insects have blood in their bodies? – Raman, 7, Washington

Dear Raman,

You probably don’t look like an insect. You don’t have feelers or wings. You keep your skeleton inside your body instead of on the outside. But what about blood? Do insects have blood like yours?

I talked about this with my friend Richard Zack. He’s an entomologist at Washington State University.

“Insects have hemolymph,” he said. “It’s very similar to blood.”

Zack told me hemolymph moves differently through the body, and it doesn’t do everything blood does.

Humans and other mammals have closed circulatory systems. That means their blood travels in blood vessels. A heart pumps the blood all over the … » More …

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How does evolution work? – Aubree, 10, Kentucky

Dear Aubree,

When I thought about evolution, I always pictured big changes that happened over long time periods—like how birds evolved from dinosaurs.

But then I talked with my friend Jeremiah Busch. He’s a biologist at Washington State University. He told me evolution is happening all the time.

“As soon as you see that evolution is occurring around us, it changes the way you think about the world,” Busch said.

There are a few ways evolution happens. These include mutation, gene flow, genetic drift and natural selection.

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Do ants hibernate in the winter? – Garrett, 10, Illinois

Dear Garrett,

When most people think about hibernation, they picture bears snoozing away the cold winter in their dens. You’re right that other animals do that, too.

I talked about your question with my friend Laurel Hansen. She’s an entomology professor at Washington State University. Her specialty is carpenter ants.

“We think most ants in our temperate climate will have diapausing larvae and what I would call overwintering adults,” Hansen said.

Diapausing and overwintering are like hibernating but not quite the same. There are a few things to know about ants to understand what these terms mean.

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How many beetles are there in the world? – Tu, 12, Utah

Dear Tu,

If beetles seem to be everywhere, that’s because they are. Some beetles stand out because they’re colorful. Think about jewel beetles and ladybugs. Others play useful and weird roles in the ecosystem—like the poop-rolling dung beetle. Their ancestors probably even ate dinosaur poop.

Nobody knows exactly how many beetles there are, but scientists have some ideas. I talked about it with my friend Joel Gardner. He’s the collection manager for the insect museum at Washington State University.

When scientists find a new species, they describe what it looks like. They give it a name. They publish that information so other people know about it. That’s called describing a species. Scientists describe new insect species all the time.

Gardner told me scientists have described about 400,000 species of beetles so far. There are many more beetles we don’t know about yet. Altogether, there are probably between 1 million and 2 million beetle species.

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If an animal has poison inside them, how are they not affected by their own poison? – Jad, 10, Georgia

Dear Jad,

From jellyfish to snakes to spiders, lots of animals use poison or venom. It helps them catch prey and defend themselves. Even the platypus and one very spicy primate called the slow loris use venom.

I talked about your question with my friend Blair Perry. He’s a biologist at Washington State University. He’s also a snake expert.

Perry told me the difference between poison and venom. They’re both toxic mixes of mostly proteins. But they get into your body in different ways. Poison is eaten, breathed in or absorbed through the skin. Venom is injected through a bite or sting.

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How long do you have to train to become a scientist? – Katelyn, Texas

Dear Katelyn,

Maybe you dream of pointing your telescope toward distant galaxies. Or zooming in on microscopic life on Earth. Being a scientist is an amazing job. You can also do science for fun—no matter your age or anything else about you. It belongs to everyone.

I talked about science training with my friend Kalli Stephens. She’s earning her bachelor’s degree in genetics and cell biology from Washington State University. WSU has a strong undergraduate research program. So, Stephens has been working as a scientist while going to school.

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How do starfish eat? – Hailey, 7, Maryland

Dear Hailey,

Starfish might have the coolest—and strangest—way of gobbling up a snack.

I learned all about it from my friend Cori Kane. She studied coral reefs when she was a biology Ph.D. student at Washington State University. Now she works for the National Oceanic and Atmospheric Administration. She writes policies to help protect the ocean and the animals that live there.

“Sea stars are probably one of the weirdest creatures. I don't know any other organism that basically barfs out its stomach to eat,” Kane said.

Yes, you heard that right. She said sea stars barf out their stomachs.

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What are microorganisms? –Trystan, 11, North Carolina

Dear Trystan,

One of my favorite things to do is look at pond water with a microscope. I love to see all the teeny tiny critters zooming around in a single drop.

I talked about microorganisms, also called microbes, with my friend Claire Burbick. She’s a microbiologist at Washington State University. She told me the key trait for microbes is size. Microbes are micro—which means extremely small.

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Do animals feel home-like in wildlife sanctuaries? – Haniya, 8, Pakistan

Dear Haniya,

There are lots of things that make a place feel like home. Your home is probably full of sights, sounds and smells that feel familiar and cozy. Those things are important for animals in captivity, too.

To find out more, I talked with Charles Robbins, a wildlife biologist at Washington State University. He started the WSU Bear Center. It’s the only grizzly bear research center in the United States.

“The most important thing to bears and probably most animals is a feeling of safety—that they’re not being hurt, and the food is good,” Robbins said. “Probably all the same things that … » More …

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When was the first bee made? – Henry, 7, Illinois

Dear Henry,

It’s easy to love bees. They’re furry and buzzy. Along with other insects, birds and bats, they pollinate about one-third of the plants we eat.

I talked about how long bees have been buzzing around Earth with my friend Silas Bossert. He’s an evolutionary biologist in the Department of Entomology at Washington State University.

“The oldest bee fossil that is really without doubt a bee is between 65 and 70 million years old,” Bossert said.

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How does the brain transfer signals to each body part to move? Yulissa, 11, Virginia

Dear Yulissa,

Your brain weighs less than 3 pounds but has the power to move your whole body. That’s because it’s part of your nervous system.

Your brain and the spinal cord that runs down your back make up your central nervous system. You also have a peripheral nervous system made up of nerve cells. These connect your brain and spinal cord to all the other parts of your body.

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How does honey last forever? Gillian, 7, Illinois

Dear Gillian,

Archaeologists exploring ancient Egyptian tombs sometimes find honey. It’s thousands of years old, but you could still safely spread it on your toast!

I talked to my friend Brandon Hopkins, professor in the WSU department of entomology, about why honey lasts so long. He told me honey is one of the only foods that never spoils.

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Dr. Universe: Do spiders sleep? - Peter, 10, South Dakota

Dear Peter,

At the end of the day, you probably curl up in a cozy bed for a little shut eye. Unlike you, most spiders have eight eyes, and they never shut any of them. They don’t even have eyelids!

I talked about spider sleep with my friend Richard Zack, an entomologist and professor in WSU’s College of Agricultural, Human, and Natural Resource Sciences. He also runs the biggest insect museum in the state of Washington at WSU. He told me that spiders and insects do rest. They nestle into a safe spot and enter a “stupor,” which means they’re very still.

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Dr. Universe: How are sea animals affected by water pollution? - Natalia, 10, Florida

If you ever visit the beach, take a look at all the animals: crabs scuttling across the sand, seals bobbing on the waves and sea stars tucked into tide pools. Maybe there are even whales spouting on the horizon. Earth’s oceans are home to thousands of creatures. But, as you know, human pollution reaches our waterways and all the animals that live in them. To learn more, I talked to my friend Erica Crespi, an associate professor in the Washington State University School of Biological Sciences. Crespi studies how animals that live in water respond to all kinds of stresses, including pollution. Read More ...

Dr. Universe: What are cells made of? – Lela, 10, Bogart, GA

Dear Lela, You have all kinds of cells in your body that do lots of different things. In fact, there are about 200 different types of cells in the human body—from blood cells to skin cells to bone cells. To find out exactly what all those cells are made of, I visited my friend Deirdre Fahy. Fahy is a scientist at Washington State University who is curious about how and why things work, including our cells. She reminded me the human body is made up of billions of cells. You might think about each cell as if it were a tiny room. But this room, or cell, is so small, you’d likely need a microscope to see it. Read More ...

Dr. Universe: Why do we have to blink? - Michael and Virgil, 3 and 5, in Sioux Falls, SD

Dear Michael and Virgil, If you’ve ever had a staring contest with a friend, you may have felt your eyes start to get tired and dry. Eventually, you just had to blink. Blinking helps our eyes stay healthy, and my friend Dr. Karen Janout, a clinical assistant professor at Washington State University, told me all about it. She said that with each blink, your eyelids help spread tears over the surface of your eyes—and you actually do this a lot. Humans blink an average of 15 to 20 times a minute, which adds up to somewhere around 5.2 to 7.1 million blinks a year. Read More ...

Why are people most commonly right-handed? Who/what deicides if we are left-handed or right-handed? Are you left-handed or right-handed? Mya, 8, Alexandria, VA

We don’t know exactly why so many people are right-handed, but one place we might look for answers is in the material that makes a person who they are: genes. The genes in your body help control all sorts of things from the color of your hair to your skin to your eyes. These traits can be passed down through generations—from grandparents to parents to you. My friend John Hinz, who is a right-handed professor at Washington State University, knows a lot about genes and the study of how organisms pass their genes through generations. Read More ...

Hey, Dr. Universe: Why do we humans get sunburns when we are out in the sun too long? - Gavyn, 13, Indiana 

Humans need sunlight to help keep their bones, blood and other body systems healthy, but too much time in the Sun can sometimes leave people with a sunburn. Sunburns often strike when the body gets too much of a type of light, called ultraviolet light, from the Sun. As your body recognizes there is too much ultraviolet light, it turns on a defense system. The immune system, which responds to invaders like viruses and other harmful things like ultraviolet light, kicks in. Some people might see their skin get red or blistered. They might feel itchy or painful. But not everyone experiences sunburn in quite the same way. A big part of the answer to your question also has to do with human cells. My friend Cynthia Cooper, a researcher at Washington State University, knows a lot about cells and how they work. Read More ...

Dr. Universe: How do trees give us air to breathe? – Jamar, 11, Vineland, New Jersey

Our planet is home to all kinds of different plants, and they help make a lot of the oxygen we breathe. To find out how plants make oxygen, I asked my friend Balasaheb Sonawane. Sonawane is a scientist at Washington State University who researches photosynthesis, or the ways plants use energy from the sun and make oxygen. He said that in a way, plants breathe, too. “They don’t have a nose or mouth,” Sonawane said. “They have tiny microscopic organs on their leaves called stomata.” Read More ...

Dr. Universe: Do flying squirrels really fly? - Gwendolyn, 9

Flying squirrels may not really fly, but they do have flaps of skin on their bodies that act like parachutes and help them glide through the air. My friend Todd Wilson told me all about it. He’s a wildlife biologist with the U.S. Forest Service in Oregon and graduate of Washington State University who researches Pacific Northwest ecosystems and the animals that call them home— including flying squirrels. Read More ...

Dr. Universe: What are bees’ wings made of? -Natalia, 13, Kennewick, WA

Dear Natalia, Bee wings may be small, but they are really strong. I learned all about bee wings from my friend Melanie Kirby, a honey bee researcher at Washington State University. Kirby said you can think about bee wings as if they were a kite. If you make a kite out of thin tissue, it might rip. But if you make it out of a strong plastic film it will be stronger. Bee wings are made of a material called chitin (KITE-IN) and it’s a lot like keratin, the material that makes up your fingernails. Chitin is what makes up the wings on each side of the bee’s body. Read More ...

Dr. Universe: What gives leaves their shapes? Please reply back. Thanks a ton! -Pronoy, 9, San Jose, CA, USA

We can find all kinds of leaves on our planet. Just think of tiny pine needles, fern fronds, ivy vines, or a big banana leaf. My friend Eric Roalson is a professor at Washington State University who is very curious about plants. He said there are a few things that give leaves their shapes. The shape of a leaf can depend on the family history of a plant, the group it belongs to, and the environment where it grows up. Read More ...

Dr. Universe: Why do we have spines? - Jessie, 10, Covina, Calif.

Dear Jessie,

Your spine is more than just a long line of bones. It’s the secret to jumping for joy, the base for all your best dance moves. Every time you run, climb, walk, and play, your spine is right there with you.

“Without a spine, our ability to move would be completely different,” Edward Johnson said.  Johnson teaches Human Anatomy in the School of Biological Sciences at Washington State University. He is very curious about how all the parts of your body work together.

All creatures with spines are called “vertebrates,” including humans. They get this name from their vertebrae: the special bones that make up the spine. Your vertebrae are different shapes and sizes, but they all connect together.

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How are seashells formed? And why are they different colors? Can seashells live or die? - Caroline, 9, Crestwood, Ky.

Dear Caroline,

Seashells come in an astounding variety. Some are curved and round, others long and tube-like. Some are smooth, others bumpy. Some are large, others small. Plus, they come in a rainbow of colors: red, green, brown, purple, pink, and more.

All that variety comes from the same source: little animals called mollusks, with a mighty muscle called a mantle.

I found out all about them from my friend Richelle Tanner, a scientist at Washington State University. She is very curious about the ocean and knows a lot about mollusks, a type of animal with a soft, moist body.

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Dr. Universe: Why do people have different fingerprints? - Mary, 12, South Carolina

Dear Mary,

Did you know even identical twins have different fingerprints? It can be hard to tell twins apart, but a close look at their fingertips can reveal who’s who. The reason lies partly in their genes, but mostly from the unique way everyone’s skin grows before birth.

That’s what I learned from my friend David M. Conley, a professor at Washington State University’s Elson S. Floyd College of Medicine.

“The reason fingerprints are unique is the same reason individual humans are unique,” Conley said. “Variation is the norm, not the exception.”

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Dr. Universe: Why are brains mushy? – First Graders, Waller Road Elementary, Puyallup, Wash.

Dear First Graders,

You’re right, brains are quite mushy. It turns out the three-pound organ between your ears is mostly made up of water and fat.

I found out all about brains from my friend Jim Peters, a neuroscientist at Washington State University.

“It’s gooey. It really is squishy,” he said. “When it is warm, it is kind of like butter.”

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Dr. Universe: Why do we have a tailbone? -Tyler, 15, East Liverpool, England

Dear Tyler,

At the very bottom of the human spine is a bone that sticks out a bit called the coccyx (cox-ix). We sometimes call it the “tailbone,” but it is actually made up of several different spinal bones.

In some animals that actually have tails, those different bones at the bottom of the spine help them move their tail around. But in humans, those bones partially fused together.

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Dear Dr. Universe: How do we talk? – Emmy, 7, Wash. State

Dear Emmy, When you were a little kid, maybe you played Peek-a-Boo or sang “Itsy Bitsy Spider.” These kinds of games and songs have a lot of the different sounds we make when we are first developing speech. A lot of humans start out playing with speech through cooing and crying. At about six months old, this cooing and crying turns to babbling. A baby might make sounds such as ma-ma, pa-pa, or ba-ba. Read More ...

Dr. Universe: What can I do to help stop ocean pollution? -Hailey, 10

It’s great to hear you want to help our oceans. After all, they do a lot for us. Life in the ocean provides much of the oxygen we breathe and is also a source of food for many animals, including humans. One of the most important things we can do to prevent more pollution is to keep our garbage, especially plastic, out of the ocean. That’s what I found out from my friend Richelle Tanner, a marine biologist and researcher at Washington State University. While a lot of plastic ends up in the ocean, it actually started under the Earth’s surface in the form of oil, leftovers of plants and animals that died long ago. Read More ...

Dear Dr. Universe: Why do flowers smell so nice? – Miles, 5

Flowers not only smell nice to humans, but also to many insects and birds who help the flowers do a really important job. Let’s imagine that you are a bee or a butterfly. You don’t have a nose on your face, but instead use your two antennae to smell things. As you fly around, you catch a whiff of chemicals floating in the air. Down below, you see a field of daisies. The flowers are releasing some chemicals, which are the building blocks of a smell. Read More ...

Dr. Universe: Why do we get morning breath? -Stephanie, 10

Dear Stephanie, If you’ve ever caught a whiff of someone’s stinky morning breath, or even your own, you know it can be pretty rotten. We can trace the smell back to tiny culprits that live in our mouths. They are called microbes and they live around your gums, between your teeth, and on your tongue. Read More ...

Dr. Universe: Why do we have five fingers and five toes? -Eli, 11, Edinburgh, Indiana

Dear Eli, While humans may be one of the few animals that can give a high five, they are one of many with five fingers and toes. Humans are part of the primate family, which also includes monkeys, apes, and even lemurs. As a member of the family, you also have fingernails instead of claws and pads on your fingertips that help with your sense of touch. Read More ...

Who created the very first chocolate bar? – Emma, 11, USA

Dear Emma,

For most of human history, people have enjoyed chocolate in a spicy, bitter drink. But when people discovered how to turn chocolate into a solid, it opened up a whole new world of possibilities.

That’s what I found out from my friend Omar Cornejo, a scientist at Washington State University who is very curious about the history and life of the cacao tree. Chocolate comes from the seeds of leathery fruits that grow on the tree.

If we cut open the fruit, we would find about 20 to 60 seeds on the inside. In ancient times, people would grind up the seeds … » More …

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May I ask how fish breathe? - Nghi, 11, Vietnam

Dear Nghi,

When you and I take a deep breath, we pull air into our lungs. That’s because humans and cats are mammals. But fish aren’t mammals. They usually don’t breathe air. They usually don’t have lungs.

That’s what I found out from my friend Michael Berger. He’s a biologist at Washington State University.

He told me that you can actually see a fish breathe water. Its face gets bigger when it takes in a big gulp of water. Just like when you take a big bite of food.

When you look at a fish, you can usually see the gill openings—called gill slits. … » More …

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Dear Dr. Universe: I would like to find out how ants are so strong. How is it possible that they can carry weight that is heavier than themselves? –Anita, 11

Dear Anita,

Ants are pretty good little weightlifters. My friend Rich Zack, a scientist at Washington State University who studies insects, knows a lot about ants. One kind of ant that he has studied can carry up to 20 times its own weight.

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What do astronauts eat in space? –Rhemi, 12, St. Louis, Mo.

Dear Rhemi,

Astronauts eat all kinds of different foods up in space. The food is often similar to what we have here on Earth. But in space, there's very little gravity. There’s very limited refrigeration, too. On the International Space Station, the refrigerator is only about half the size of a microwave. That means scientists who prepare and package astronaut food have to do it in ways that take up very little room and don’t need to be kept cold.

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Why do we have different feelings? - Charan and Aishwarya V., 10 & 8, Rutherford, New Jersey

Dear Charan and Aishwarya,

Imagine you are playing a game of soccer and your best friend is on the opposing team. The sun is out, you are having a great time, and you score the winning goal. You’d probably feel pretty happy and so would your team.

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Dear Dr. Universe: Do you know how human and animal interactions help our mind grow? Does it help us? Does it do nothing? This has fascinated me for a very long time. - Gabby G., 11, Berlin, VT

Dear Gabby,

Our brains are pretty busy. They are constantly thinking, feeling, and sensing our world. One thing that can help some people relax is spending time with an animal friend. You might play fetch with a dog, sit with a cat, brush a horse, or even watch a goldfish zip around its bowl.

People who spend a lot of time with animals might tell you that something special seems to be going on here. But scientists are looking for evidence and want to find out for certain just what is going on. They want to know … » More …

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What is the smallest insect on Earth? -Laurenz, 8, Molino, Philippines 

Dear Laurenz,

When I saw your question, I set out to explore with my bug net and a magnifying glass. I was searching all around for tiny insects when I ran into my friend Laura Lavine, a Washington State University scientist who studies bugs.

She said there are nearly a million different kinds of insects on Earth. The smallest of all the known ones are called fairyflies.

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