When you see the word “hair,” what do you think of? Probably the stuff on your head. There are about 100,000 hairs up there. But you actually have about 5 million hairs altogether! In fact, you have about as many as an ape does.
People usually treat hair as a decoration. But it actually has a lot of jobs to do. It cushions minor blows. It also keeps the sun off and keeps us warm. It can tell us if someone or something is touching us. It lets us know if the temperature changes. And tiny hairs—eyebrows, eyelashes, and nose hairs—have jobs, too. They help keep dirt and other stuff out of places where it shouldn’t be.
Fingernails are survival tools, too. Try getting a pin or a coin off the floor without using your nails. Or try to scratch that itch on your scalp.