Navel

The navel (clinically known as the umbilicus, colloquially known as the belly button, tummy button or umbilical dip) is a scar on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, and it is quite conspicuous in humans. Other animals' navels tend to be smoother and flatter, often nothing more than a thin line, and are often obscured by fur as well.