the birds and the bees

"Many behavioral adaptations are designed to improve organisms' chances of reproductive success. Consider, for instance, the wide variety of species in which females actively choose which male to mate with. In many such species, females demand material goods and services from males in return for copulation opportunities. For example, in one type of moth, males have to spend hours extracting sodium from mud puddles, which they then transfer to prospective mates, who use it to supply their larvae with an important nutritional element. In the black-tipped hangingfly, females insist on a nuptial gift of food before they mate. They reject suitors bringing unpalatable food, and they tie the length of subsequent copulation to the size of the nuptial gift. The adaptive value of trading sex for material goods that can aid the survival of an organism and its offspring is obvious, but the evolutionary significance of other mating strategies is more perplexing."

"A substantial portion of bird species are predominately monogamous, as are a small minority of mammals, such as woves and foxes. As in humans, however, many monogamous relationships are more appearance than reality."

"The hypothalamus plays a major role in the regulation of basic biological drives related to survival, including the so-called "four F's": fighting, fleeing, feeding, and mating"

studying for psychology is fun :-)