Ever wondered why you get goose bumps?

· They go by different names -- goose bumps or goose pimples -- but they are the same thing: those little bumps that appear on your skin when you are cold or afraid.

Here's what happens when a person gets cold: The muscles in human skin (yes, everybody has muscles in their skin) contract, and that causes the little hairs that cover your body to stand up.

That hair-raising process can make you a little warmer in two ways. For one thing, hair that stands on end traps more air that can warm your skin than hair that's lying flat. And, as with all muscular activity, this skin muscle movement produces heat, which is another way your body tries to help you warm up.

Things happen a little differently when you are afraid, but the result is the same.

Fear makes your body produce adrenaline, a chemical that prepares you for emergency action. It makes your heart beat faster, which you may have noticed if you have been in a scary movie and felt your chest suddenly pounding, and it makes your muscles tense, which we've learned causes skin hairs to rise.

Raised hair caused by goose bumps makes some animals appear larger and may scare predators. Scientists think that a long time ago, when people were covered with heavy hair, goose bumps worked the same way.

So how did goose bumps get their name? They look like the bumpy flesh of a goose with plucked feathers.

-- Valerie Strauss

SOURCE: "The Handy Answer Book for Kids (and Parents)" by Judy Galens and Nancy Pear