Boys can be just as committed to childcare as girls.

Emperor penguin parents work together to raise their young. Directly after laying her egg, the female takes off to feed in the ocean for two months, leaving the male to incubate the egg. The chick’s first meal comes from its father in the form of crop milk. Prolactin, the hormone that causes lactation in mammals, is responsible for the production of crop milk as well.

As teenagers, some boys babysit.