We have all seen this moment countless times: a baby enters the world and bursts into tears. It is so common that we rarely stop to wonder why it happens. Why do newborns cry instantly after birth?

Add Yahoo as a preferred source to see more of our stories on Google. There aren't many things cuter than kittens and babies — though puppies would definitely make the list as well. Infants and little ...

We're actually born smiling. 3-D ultrasound technology now shows that developing babies appear to smile even in the womb. After they're born, babies continue to smile (initially mostly in their sleep) ...