Evolutionists like Dawkins pose that most organisms are in fiercest competition with members of their own species. You and I compete for identical resources: mates, jobs etc.
Other species have mostly arranged not to kill one another in these competitions. E.g. vipers & komodo dragons don't bite while wrestling. Walruses get pretty ripped-up, but usually don't die.
Ganging up to kill seems to be mostly a primate thing.
Male lions will kill cubs fathered by another male without remorse. It is not the same as our primate instincts of war, but remarkably close to ethnic cleansing.
Ganging up to kill seems to be mostly a primate thing.