The second implicit message of the exhibit turns the focus from animals to man, using the plastic sexuality of animals to critique our own society's rigid sexual classifications. It is no accident that the exhibit ends with sculptures, videos and text about bonobos, sexual voracious apes that, along with chimpanzees, form humanity's closest living animal relatives. For bonobos, oral sex, sex with children, same sex pairings, in fact, nearly any imaginable sex act, are a daily part of life. Sex is often used as payment for food and to assert dominance, and only sex between mothers and adult sons is taboo. If many behaviors thought exclusive to humans are seen in our relatives, the exhibit asks, what behaviors of theirs _should we consider natural to _us?