Kids have 20 baby teeth, and adults usually have 32 teeth.

Leaves change color in autumn because the green chlorophyll fades away.

Triceratops had three horns on its face and a big bony frill.

Tomatoes and cucumbers are actually fruits because they have seeds.

Saturn has more known moons than any other planet in our solar system.

Pound for pound, spider silk is stronger than steel.

Arctic terns fly from the Arctic to Antarctica and back every year — the longest migration of any animal.