Aww. Aren’t penguins the cutest? With all their waddling and flappy little arms. Adélie penguins look particularly adorable, standing at just 70 centimeters (27.5 inches) with beady little eyes.

But don't be fooled by their charming appearance. When Dr George Murray Levick made his observations on their sexual behavior in 1911 and 1912, it was deemed too inappropriate to ever be published. You might consider that standard in prudish Edwardian England, but even by today’s standard, some of it is pretty extreme.

Far before the sexual liberation of the 1960s, penguins were ahead of the curve by engaging in promiscuous sex between unpaired male and female penguins. There were also records of homosexual sex between male penguins.

So far, no problems by modern standards. But wait. On his Antarctic Expedition, Levick also observed instances of Adélie penguins engaging in rape, gang rape, sexual and physical abuse of chicks, as well as necrophilia with penguins, some of which had died the previous year.

Levick blamed this "astonishing depravity" on "hooligan males." So shocked, he wrote down his observations in Greek so only educated gentlemen could understand. His code seemed to work, and his work wasn't published until 2012.

In 1998 more penguin depravity came to light, when people observed ad é lie penguins using stones to pimp out females for prostitution . They also reported that some of the prostitute penguins tricked the males into thinking they would have sex by performing an elaborate courtship ritual, then run away with their stones.

Pingu will never be the same.

Main image credit: Jonathan E. Shaw/Flickr. (CC BY-NC 2.0)