Is there a species other than humanity that slaughters one another in such high numbers? Serious question; I don’t know the answer.

I know intra-species slaughter is fairly common in some predators, like lions. And of course reptilians and ichthyoids will cannibalize one another.

But that’s without malice aforethought — just “crimes” of opportunity. Perhaps like most human characteristics, war and genocide are very human indeed.