Do all animals have belly buttons?

Your navel is a wonder of nature that reminds you of where you came from

Humans have belly buttons because before we are born we are connected to our mothers via an umbilical cord. This is a tube that delivers nourishment to the embryo (unborn baby), and removes its waste. It runs from the placenta – an organ in the mother’s body that provides a source of food and oxygen – to the tummy of the embryo. Once a baby is born, it can get nourishment, such as milk, through its mouth, so the umbilical cord is no longer needed. The cord shrivels up and drops off after a few weeks. Your belly button, also called a navel, is basically a scar from where the umbilical cord used to attach to your tummy.

Animals with placentas

Humans are part of the group of animals called mammals, and other mammal babies develop inside their mother in the same way. Human belly buttons are quite large and obvious. They are also visible in other big mammals such as dolphins and orangutans. Smaller mammals like cats and dogs also have them, but the scars do not form large holes and they are often covered by hair or fur.