A belly button, sometimes called a navel, is something everyone in the world has! From Alaska to Zimbabwe - and every place in between - people have belly buttons. And they're always in the same place on their bodies.

As a baby develops inside his mother, he floats in fluid inside his mother's womb. While the baby is in there, he cannot breathe air or eat food. That's where the umbilical cord comes in. The umbilical cord is a flexible tube that carries oxygen and nutrients from the mother to the baby. It also carries wastes away from the baby back to the mother, so she can get rid of them. Your belly button marks the spot where your umbilical cord was once attached.

When the baby is born, he lets out his first cry, letting everyone know he can breathe on his own. He will soon be drinking milk and getting rid of wastes on his own - as anybody who has seen a dirty diaper will tell you!

The brand-new baby doesn't need an umbilical cord anymore. The doctor cuts the umbilical cord and a tiny stump is left. When this stump falls off after a few weeks, the baby is left with his very own baby belly button. It might be an innie or an outtie - which kind do you have?