So we humans have Jack the Ripper, the Boston Strangler, Ted Bundy, Gacy, Dahmer, et al…are there animals out there who hunt and prey upon their own kind, just for thrills?
I know there are lions who kill other lions, and bears that kill other bears-but that’s usually due to a fight over something they need like territory or resources. What I’m talking about is an animal, let’s say a house cat, who creeps out at night stalking other cats and when opportunity knocks, he moves in for the kill. Or perhaps a chimpanzee who stalks another chimp, then rapes and kills her-not because she’s a threat to his food supply or territory, but because he enjoys it. And he enjoys it so much that he does it again and again. Does this happen in the animal kingdom or is this strictly a human phenomenon?
I know of some kennel dogs (edit: dogs when kept in the kennel – peoples pets) that could not be kept with other dogs, because they always got in fights, and I know of one horse that required her own pasture… But I have no idea if that’s common with other animals.
In both cases, a fight or whatever it was never ended in death, just injury.
Cats seem to hunt and kill from instinct, even if they are well fed. That may all be territorial too. You seem to be asking about animals that ‘enjoy’ killing, and that would be hard to determine.
Joseph Conrad writes that non predator animals, like doves, do not have built in prohibitions against killing of own species, so if locked up in a cage the stronger may kill the weaker as part of run of the mill fighting. Except, of course, there is no “thrill” involved. The cage would basically prevent the beaten up individual from running away which would have been the natural outcome of the conflict. By contrast, the predators and humans have stronger prohibition against seriously damaging of own species, especially when the defeated individual shows submission.
Maybe the alleged “cannibal rat” would be an animal analogy to serial killer. Allegedly if several rats are kept in captivity without food until one of them kills and eats the rest, the resulting survivor becomes so violence prone and “anti social” by rat standards that the local rats flee in terror.
If they have the chance, quite a few species of the weasel family (minks, wolverines, ferrets etc.) kill more than they’re able to eat at the moment and then try to store the cadavers for leaner times. I don’t know if that qualifies them as serial killers, though. It’s more of a hamster-type motivation than a serial killer motivation. But it can look pretty nasty if e.g. a wolverine cuts loose in a flock of sheep or reindeer
It’s not uncommon when the dominant male loses his grip over his group and a new dominant male takes over, he will kill (or try to kill) the children of the former male.
Certain species of greebs raise more chicks than they can support and then set out to kill a number of them.
Also elephants have been known to simply not tolerate lions and hyenas. They will attack them and remove them even if there is no threat.
Its worth considering that serial killers represent extremely rare deviant behavior. So it is not quite apples to apples to compare human serial killers to animals having normal competition for territory or dominance. Considering the rarity, it seems like it would be difficult to observe analogous behavior in animals. If one in a million bears had a desire to kill other bears for pleasure…would we be likely to ever find out? Would we be able to tell the difference from normal competition for females, territory, or dominance?
There are animals known to occasionally kill for fun. Dolphins, for instance, have been observed killing baby porpoises (and gang-raping female dolphins) just for the heck of it.
The chimp thing seems pretty rare in chimps - the linked article says they’ve seen it for sure one other time and that there’s evidence to suggest a few more incidents. Then again, chimps seem to wage war, also.
Depending on your semantic niggling about the definition of “animal,” humans are a species of chimpanzee, and essentially vice versa, or we are so much the same that the differences are probably exaggerated in human minds. If humans have serial killers it seems likely other chimp species share that trait.