Is there any evidence of mammals (besides humans) being serial killers or murdering their own species for fun?

Boys of Columbine were mass murderers NOT serial killers

There is a surprisingly stark contrast with these two types of...evil?... I mean psychological motivations, planning and end-game decisions, self worth distortion and delusional angst about those who challenge their character, tools, MOdus Operandi (lol),

I mean, the mass murderer is a murder suicide every time it seems-- killing those who challenged their character and way of life and made them unable to be happy or forced into self sacrifice for their world--- delusional of course

The serial killers always have a sexual component- I mean, seriously, Gacy, Dahmer, Bundy - all of their serial killings that fit their pattern happened to be for their own sexual pleasure and they disposed of their "shame" after (Bundy , I think, was disposing of the woman who broke his heart after he brutalized "her" with physical & sexual torture)

Fun is hard to use here.

Dahmer was caught because his victim promised to be his friend and stay there with him but he had to untie his hands, let him go to the bathroom, and promise to put the knife away and promise not to kill him. They hung out for a while, drinking beer in the living room of Dahmers apartment. Dahmer was all alone with a crap job, no real friends, no money, and a bad case of ( sociopathic + borderline personality ) who had major clinical depression + no health coverage + no one to notice ..... would you call that fun?

Gacy was way more of the personality that killed for fun (addiction)

My dog kills squirrels for fun. Let us fall down the rabbit hole from there....

Killings with no purpose...

Well animals (such as humans) have always and continue to kill each other for infinite reasons and it's not always clear to us if there was a purpose for 2 creatures to fight to the death...

Look into insects! I bet that they go on killing sprees!

/r/askscience Thread Parent