Dear Jules,

Sometimes my stomach growls so loudly that other people can hear it. It’s pretty awkward in meetings.

I asked my friend Ed Johnson why that happens. He teaches classes about the human body in the School of Biological Sciences at Washington State University.

He told me the rumbling noise happens because of what’s going on inside your gut.

“The sounds you hear are the fluid and gas that’s in your digestive tract moving around,” Johnson said.

The digestive system cycles through a lot of fluid—about 9 liters every single day. That’s the same as four-and-a-half 2-liter soda bottles.

Some of that liquid comes … » More …

Dear Ines,

I have gray fur. But sometimes I think it’s getting grayer—like my human friends’ hair does as they get older.

I asked my friend Jiyue Zhu about that. He’s a biochemist at Washington State University.

He told me it’s a mystery.

“We still don’t completely comprehend this,” Zhu said. “It’s an active area of research.”

Aging seems to be related to the way cells duplicate.

DNA is a set of instructions for making your body. You keep a copy of your DNA folded up inside each of your cells.

All those cells have different life spans. Some, like your skin cells, … » More …

Dear Annabelle,

I love a peanut butter and tuna sandwich. But when I was a kitten, my school outlawed peanuts. My classmate was super allergic to them. So, we had a rule to keep our friend safe. I packed plain tuna fish instead.

I talked about that with my friend Travis T. Denton. He studies medicinal chemistry and neuroscience at Washington State University.

He told me that epinephrine is the medicine people use for a serious allergic reaction called anaphylaxis. It comes in an auto-injector, or EpiPen.

<img width="396" height="88" loading="lazy" class="alignnone size-medium wp-image-8267" src="https://s3.wp.wsu.edu/uploads/sites/2332/2025/10/Epi-Pen_2016-396x88.jpg" alt="An autoinjector for epinephrine lying on its side. It's mostly ... » More …

Dear Eli,

I love to go for a walk with my dog roommate. Sometimes we see the moon in the sky—even though it’s daytime.

I asked my friend Michael Allen why that happens. He’s an astronomer at Washington State University.

He told me that we have to ask “what is a day” to answer your question.

“The sun lights up the earth,” Allen said. “Since the earth is a round ball, only half of the ball can ever be lit up at any one time.”

The side of the earth that the sun shines on experiences day. The side that faces away from … » More …

Dear Rachel,

Every spring, I see spiny bugs that look like tiny alligators. They spend all day chomping up other insects outside my window.

I asked my friend Rich Zack about them. He’s an insect scientist at Washington State University.

He told me those spiky gobblers are immature ladybugs.

The ladybug life cycle includes complete metamorphosis. They undergo big body changes to become adults. An insect that does that is holometabolous.

“Millions of years ago, holometabolous insects split up their duties between the immatures and the adults,” Zack said. “An immature’s job is to feed. An adult’s job is to mate.”

There are … » More …

Dear Macmillan,

There are some amazing deadly things out there. Like a frog that oozes poison from its skin. Or a jellyfish that uses itty bitty hooks to inject venom into its prey.

But it turns out the most poisonous thing on Earth is everywhere. It’s in our soil. It’s in our water. It might be in your kitchen.

It’s a species of bacteria called Clostridium botulinum.

I talked about it with my friend Susie Craig. She studies food safety at Washington State University.

She told me that C. botulinum makes the toxin that causes botulism. People can get it by eating … » More …

Dear Izzy,

My coworkers sometimes forget that I’m a cat—until I reach out a paw to shake their hand. At first glance, cat and dog paws seem very different from human hands and feet.

I talked about that with my friend Natasha Hottmann. She’s a veterinarian at Washington State University.

She told me that a dog paw is actually super similar to a human foot. Dogs just walk on their toes—like they’re wearing invisible high heels. That’s called digitigrade locomotion.

“People think, ‘Oh, their knee is backward’ or something—but it’s not their knee,” Dr. Hottmann said. “It’s the point of their heel, which is … » More …

Dear Prince,

Germs are tiny organisms—also called microbes. They’re so small you have to zoom in with a microscope to see them. They can be bacteria, viruses, fungi or other teeny things. Some microbes make us sick. Some don’t bother us at all. Some help us out.

I talked about all that with my friend Eric Lofgren. He studies infectious disease at Washington State University.

He said there are two main reasons we have germs on our skin. We pick up some microbes from the environment. Some live on our skin all the time.

“The world is full of microbes,” Lofgren said. “They’re very … » More …

Dear Prince,

When I was a kitten, I saw a movie about shark attacks. It made me nervous to go into the water.

I talked about that with my friend Nora Hickey. She’s a fish veterinarian at Washington State University.

She told me that sharks don’t eat people.

Many sharks can’t even bite. They have mouths adapted to sift sand or slurp up plankton.

Sharks that can bite don’t hunt humans. They eat prey with a thick fat layer like seals and sea lions. Muscly animals like birds, cats and people seem to taste bad to sharks.

“Even if they bit you, … » More …

Dear Colleen,

When I was little, I liked to move the radio dial in the car. I could hear different channels with music or talking. Plus, static in between.

My friend Ben Belzer reminded me of that when we talked about your question. He’s an engineer at Washington State University.

“Your cell phone is basically a digital radio,” Belzer said.

Any place with cell phone coverage gets divided into cells. They could be six-sided hexagons like the cells in a beehive. Or they could be any shape with flat sides. The size of the cell depends on how many people live there. A … » More …