The typical scenario between the sexes of much of the animal kingdom is that males work for the opportunity to mate with females and thus spread their genes. This work often consists of providing females with gifts such as food, as well as risking his life in competition with other males. The female, on the other hand, is a selective creature, preferring to mate with males who will pass on good genes to her offspring. She also has to make sure she is provided for to some degree, so her offspring are fed.