I've got three Terriers patrolling the property. They only weigh about 20 pounds each, 3x20=60 not much survives the encounter.
Mostly when I trap something and release it someplace else, I'm saving it's life.
I've got one Terrier that exemplifies the old saying, "it isn't the size of the Dog in the fight that counts, it is the size of the fight in the Dog". He has no conception of size, feels no pain and is absolutely ferocious when his prey instinct kinks in. He is eleven now, so obviously he is pretty good at what he does, he survived.