"Adélies gather at their colonies in October to start to breed. They have only a few weeks to do that and young adults simply have no experience of how to behave. Many respond to inappropriate cues. Hence the seeming depravity of their behaviour. For example, a dead penguin, lying with its eyes half-open, is very similar in appearance to a compliant female. The result is the so-called necrophilia that Levick witnessed and which so disgusted him."