Female field crickets trade food for sex. Female ladybugs are wanton--they don't even need food to be persuaded to leap into bed. Recent discoveries have destroyed the old notion that males are natural philanderers and females are naturally chaste--it now turns out that, in most species, the more promiscuous females have more and healthier children. But why? And what do females find attractive in a guy, anyway? That depends. Female Australian seaweed flies, for example, won't have sex with a fellow unless he can physically overpower them. And where do humans fit in? Find out...

This episode includes interviews with Ned Place of the UC Berkeley Hyena Project, Mike Majerus, ladybug specialist and evolutionary biologist at Cambridge University, and Martie Haselton, an evolutionary psychologist at UCLA.

And it features songs such as the ladybug promiscuity song and the hyena song.