Lots of animals have been observed to kill others for no known or obvious reason; primates and dolphins are two I’m aware of. My working dogs would, too, consid

Lots of animals have been observed to kill others for no known or obvious reason; primates and dolphins are two I’m aware of. My working dogs would, too, considering they wouldn’t eat the pests they killed and there was no upside for them other than praise. That should count I think.