If Freud had known more about the birds and bees, he might never have fantasized his theory of penis envy. In fact, a lot of theories about what sex is or ought to be might be vastly different if they were more firmly grounded in biology than in romance. The truth is: What passes for the story of the birds and the bees is a bedtime tale for innocents that leaves out more than it tells. In the reality of the wild, birds, bees, butterflies, snails—even orchids and avocados—“do it” in ways that would make the erotic Hindu sculptures at Konarak blush all the way down to their stone toenails. A tableau of nonhuman sexual strategies includes cannibals, transvestites, hermaphrodites, homosexual rapists, males with two penises, and plants that deceive, seduce, and kill. When it comes to mixing genes—and biologically, that’s what sex is all about—anything and everything goes.

There are almost as many ways and positions for “doing it” as they are creatures on the face of the Earth. Our human repertoire of seduction techniques seems unimaginative by comparison. Some animals and plants change sex as blithely as humans slip into evening clothes. Others resort to trickery—the biological equivalent of our sexual con games. A few animals even give up their lives for sex, but unlike us humans, they don’t have any choice in the matter. In the nonhuman world, sexual behavior is genetically programmed. Here, sex is straight and unadulterated. Nobody worries about who’s on top or who comes first or whether orgasms are clitoral or vaginal. There are no value judgments attached—no “crimes against nature,” sexual deviates, “unnatural” sex acts. Evolution favors whatever strategy best enables an animal or plant to pass along its genes and leave successful offspring.

It’s fun to be a voyeur in the world of nonhuman sex, but there’s a more serious reason for paying close attention to the birds and the bees. Training binoculars on nonhuman erotic windows can provide new biological perspectives on human sexual behavior—particularly taboos and discrimination, rape, wife-beating, and possibly other forms of sexual aggression. First, however, it’s necessary to give up some of our human chauvinist ideas. Excerpted from my book "How To Have Sex If You're Not Human"