Do all mammals have a belly button like humans? And will it remain visible?

Answer

Dear Franky,

the navel is in fact a kind of scar: it indicates the former place where the umbilical cord attached to the actual body. Before birth, several blood vessels run through the umbilical cord between the fetus and its membranes.

These navel blood vessels supply, among other things, nutrients to the fruit. Mammals receive these nutrients from the mother via the placenta, birds and reptiles obtain this nutrition mainly from the bulky egg yolk.

At birth, the umbilical cord tears (or is bitten/cut) and dries up completely in a few days, while the abdominal wall itself closes slowly at the navel.

In every animal species in which an umbilical cord is formed during embryonic development, an umbilical cord eventually also occurs: these are reptiles, birds and mammals, including humans. While the navel in humans is a very conspicuous structure, in many animal species it is no more than a slight thickening (so no pit!), sometimes not even directly visible unless as a place where the normal hair pattern is slightly disturbed (in mammals) . The navel can often be felt as a lump in the midline of the abdomen