Why do We have Belly Buttons
When a mother is pregnant she feeds her child through the umbilical cord. This cord is attached to the placenta and after birth is no longer needed. A belly button is where the umbilical cord used to be attached.
As babies, we are connected to our mothers by umbilical cords. As we leave the womb, this umbilical cord is severed by doctors, and a few days later falls off. What's left is your belly button.