natural instinct

[eugeniakm16]

When women give birth, why don't they have a natural instinct to clean their babies with their mouths?

[roslynym69]

They in fact still do.I will copy here a text from the Facebook page Badassmotherbirther which is a full answer to your question.
Mammals are known to lick and clean their young immediately upon birth. This is done for a few reasons:
to remove the scent of birth to ward off predators
to consume all the nutrients of the afterbirth
to begin the socializing of the newborn
to ingest any bacteria that can signal mommy?s breastmilk to pass on antibodies to baby through her breastmilk
to bond with baby
to stimulate the baby to transition to life outside the womb

Mammals still lick their newborns and eat the afterbirth. Except for most humans. But humans at one point in time used to exhibit all of these same behaviors. We have evolved since then and do not feel the need anymore to keep predators away, we stimulate baby in other forms and have other ways to do all the things we once worried about that triggered us to lick our babies so instinctively. 2 cultures today can still be seen licking their newborns, the Tibetans and Inuit.

Most of us have the urge to lick but resist the urge to do it and we have evolved our licking instinct into smelling our babies, kissing them vigorously, holding them close and we have returned to consuming our placentas. all this also sends your body signals on what anti-bodies to send your baby through breastmilk, it stimulates your baby, bonds and socializes him.

But some mothers still have the strong urge to lick their newborns. And they do just that. A physiological necessity. A calling from ancestors. Instinctual acts of love and ensuring the survival of young.
PhotoCred: Senhoritas Fotografia