Dear Grant, William and Kate,

When I was a kitten, I liked to scratch tree trunks. I loved sinking my claws into their bark. Now I mostly hug trees—but I still love the way bark feels under my paws.

I asked my friend Henry Adams why trees have that tough outer layer. He’s a tree scientist at Washington State University.

He told me that bark protects trees.

“Bark is like our skin,” Adams said. “It protects trees from all kinds of attackers that might want to get in—like viruses, bacteria, fungi, insects or even non-living things like fire.”

Dear Kingston,

When we think about orbits, we usually picture the Earth zooming around the sun. But does the sun just sit there? Or is it on its own journey?

I asked my friend Guy Worthey. He’s a space scientist at Washington State University.

He told me that an orbit happens because the gravity from something big pulls on a moving object. The sun has lots of gravity because it’s ginormous compared to Earth. So, that gravity pulls on the Earth and holds us in orbit.

But our sun isn’t the only star. It’s one of many, many stars in the Milky … » More …

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 … » More …

Dear Seth,

Since I’m a fluffy cat, my fur protects me from the sun. But my hairless cat and human friends use sunscreen when they go outside.

I asked my friend Michael Smerdon how it works. He’s a biochemist at Washington State University.

He told me that the sun puts out different kinds of light. Some light is visible to humans. Some is invisible—like UV light.

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.”

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 … » More …

Dear Ziyonna,

What happens if you do a big jump? Your body goes up into the air. But then it comes back down again. The reason you don’t just keep going up, up, up is because the force of gravity pushes your body and the Earth together.

It turns out gravity is a big reason the sun is so hot. That’s what my friend Michael Allen told me. He’s an astronomer at Washington State University.

He said that, at first, the universe was like a thick soup of gas and dust. Then, gravity pushed some of the gas and dust together. That’s how stars … » More …

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 … » More …

Dear Daniel,

When I think about dinosaurs, I usually picture the big ones. I think of triceratops with its pointy horns or apatosaurus with its long, long neck.

I asked my friend John Blong if those dinos ever lived with people. He’s an environmental archeologist at Washington State University. He studies early humans.

He told me that people and dinosaurs never lived at the same time. Well, mostly.

Dinosaurs went extinct 66 million years ago when a giant asteroid crashed to Earth. It threw up tons of dust and soot. It made Earth super cold and dark. It stayed that way for a … » More …

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 … » More …