Animal sexual behaviour - Wikipedia, the free encyclopediaThis article is about the sexual behaviour of non-human animals; see also Human sexuality and Sexual reproduction. takes many different forms, even within the same species. Among animals other than humans, researchers have observed monogamy, promiscuity, sex between species, sexual arousal from objects or places, sex apparently via duress or coercion, copulation with dead animals, homosexual, heterosexual and bisexual sexual behaviour, situational sexual behaviour and a range of other practices. Related studies have noted diversity in sexed bodies and gendered behaviour, such as intersex and transgender animals.The study of animal sexuality (and primate sexuality especially) is a rapidly developing field. It used to be believed that only humans and a handful of other species performed sexual acts other than for procreation, and that animals' sexuality was instinctive and a simple response to the "right" stimulation (sight, scent). Current understanding is that many species that were formerly believed monogamous have now been proven to be promiscuous or opportunistic in nature; a wide range of species appear both to masturbate and to use objects as tools to help them do so; in many species animals try to give and get sexual stimulation with others where procreation is not the aim; and homosexual behaviour has now been observed among 1,500 species and in 500 of those it is well documented.