In his pioneering book Female Control (1996), Eberhard presented the case that female genitalia – be they vaginas, cloacae or spermathecae – are far more than just inert tubes for ejaculate. They are active organs that can store, sort and reject sperm through their architecture, physiology or chemistry. Females can dump the semen of unappealing suitors, actively speed chosen sperm on a fast track to the ova, or let them languish in a tortuous maze of ducts. The way Eberhard saw it, once insemination has taken place, it is the female who sets ‘the rules of the game
