Potatoes were the first vegetable grown in space.

Your body has about 600 muscles.

Earth's crust is broken into giant pieces called tectonic plates that move very slowly.

Some frogs can freeze solid in winter and thaw out alive in spring.

Pumpkins are a kind of fruit, because they grow from a flower and hold seeds.

An octopus has three hearts and blue blood.

Hummingbirds are the only birds that can fly backwards.