Dolphins, penguins and sea otters… Brian Switek in Slate says they are jerks.

Later researchers rediscovered what Levick had seen. Rather than being deviant, the behaviors were a regular part of penguin life, triggered by males associating a rather flexible interpretation of a female’s mating posture with receptiveness. As Natural History Museum, London ornithologist Douglas Russell and colleagues reported in a preface to Levick’s belatedly-released report, this behavior is so ingrained that when a researcher set out a dead penguin that had been frozen in such a position, many males found the corpse “irresistible.” In a bit of weird field work, the same researcher found that “just the frozen head of the penguin, with self-adhesive white O’s for eye rings, propped upright on wire with a large rock for a body, was sufficient stimulus for males to copulate and deposit sperm on the rock.” I fear I’ve just made the Socially Awkward Penguin seem just that much more socially awkward.

As Douglas and colleagues stressed in their preface to Levick’s report, though, “the behavior [displayed by hooligan males] is clearly not analogous to necrophilia in the human context.” That fact can easily be lost when one is appalled by an animal acting out a human taboo. Levick was aghast because he viewed the penguins in human terms—as little gents and dames dressed to the nines. The sentiments about proper human behavior were impressed upon the penguins, and vice versa. For if such awful displays occurred in nature, what might that say about our own actions?

What sea otters, dolphins, and penguins sometimes do to one another in their attempts to mate can make us feel queasy, but this is just one sort of animal behaviors that have been unsettling us since the Victorian era.

What we might perceive as aberrant behavior starts early—especially violence. Inside pregnant sand tiger sharks, for example, the first embryo to grow large enough rapidly devours all the other unborn sharks in its shared womb. In other species, post-hatching battles begin almost immediately. Young cattle egrets will peck and harass weaker siblings, going so far to push them out of the nest and to their doom. Such behavior led ornithologist Douglas Mock and colleagues to write “Occasionally, the pen of natural selection writes a murder mystery on the pages of evolution.”

Parents can be as bad as siblings. Among birds, parents under stress to provide for their offspring during rough years may boot eggs from their nests or kill some of their own chicks so that others might survive. As ethologist Sarah Hrdy has observed, there are various reasons for infanticide. Ground squirrels, hyenas, and lions may eat infants of their own species just for a snack. Wannabe mother primates may steal the baby of another and unintentionally starve that infant in a phenomenon called “aunting to death.” Dominant wild dogs may kill the offspring of subordinate members of the pack to make sure the alpha’s infants get the most food. And amorous males of various species, including the noble lion, kill infants to make their mothers available for breeding again. All of this is only the barest catalog of common and widespread phenomena in nature that we often shy away from examining, as we have great difficulty divorcing our own sense of morality from a wilderness that does not and cannot share our values.