Why do we have belly buttons?

Before birth, a developing baby cannot eat or breathe on its own, so it is connected to the mother placenta by the umbilical cord. This cord carries oxygen and nutrients to the baby and removes waste, acting as a lifeline throughout pregnancy. After birth, the cord is clamped and cut because the newborn can now breathe and feed independently. The small stump that remains dries up and falls off within one to three weeks, leaving behind the scar we call the navel or belly button. Whether it becomes an innie or an outie depends on how the scar heals, not on how the cord was cut. Nearly all placental mammals have a navel, though in furry animals it is usually hidden and far less noticeable than in humans.