Quote from : Bonk: The Curious Coupling of Science and Sex Book

Homo sapiens is one of the few species on earth that care if they’re seen having sex. The impala is unconcerned. The dingo roundly flaunts it. A masturbating chimpanzee will stare straight at you. To any creature other than you and I and 6 billion other privacy-needing H. sapiens, sex is like peeling a mango or scratching your ear. It’s just something you do sometimes.