I got two mice in one trap once. Yup.
I woke up my roommate and boasted: Look!! 2 in one trap!!! (Spend a winter in Tahoe and tell me you don't have mice in the garage... or- mice you have killed in the garage.)
killed around a dozen red squirrels that decided to build a nest in the rafters of my re-modeled home. Yup. they had to die. Can't have squirrels building homes inside what will soon be your home. Stupid squirrels.
I put a hole in the wall from missing a possum with my .22 once. Got him the second shot, though. Little prick came right into my house and decided it'd be fun to nestle in my laundry. My wife kept shouting... don't shoot the washing machine!!! I didn't.
Killed a fox that thought it lived in my house too. I came home... walked in the door... saw a fox sitting at the other end of the living room like it was Thursday... just looking at me. So I walked around the corner, grabbed the .22, and shot it. End of story.
Coyotes killed the cats. Would have shot them too, had I the opportunity. That's the price you pay for letting them be non-house-cats. Can't do that in some places.
Had a bear decide to eat the neighbors garbage outside my bedroom window. Didn't shoot him, though. Looking out the window and locking eyes was enough terror for one evening. He ran too.
Live in the mountains, people, and critters get inside your life. It's usually not welcome, either. Get used to it, or go back to the city.
Next time you complain about killing a porcupine trying to sustain life below your chairlift- ask yourself: How many animals died when this ski resort was clear-cut?