I felt bad this morning because I had to kill a little mouse.

We keep mousetraps set in the basement, because otherwise mice move in from outdoors and start breeding amongst all our belongings and boxes. Our cats don't go down in the basement (too much oil, dirt and toxin dangers), otherwise there would be NO mouse problem at all. Our cats keep the main part of the house totally mouse-free.
I don't use mouse/rat poison because 1)the cats might eat a dying poisoned mouse if they ever got hold of one, and 2) it's a way slower way more painful death than a mousetrap. I hate the idea of little mice crawling around in agony while they die from poison.

In the fall and winter, I find at least one mouse a week dead in my traps- their necks instantly broken. Very, very efficient.
This morning I was sad to find a mouse that somehow had survived this- had the bar down on his neck but was still very much alive. I felt really bad. I knew I had to kill him quickly to end his suffering. Just couldn't bring myself to smash him with something. So I had to drown him. I filled abucket with warm water, dropped him in trap and all, and weight him down with a flowerpot. I felt so BAD! Came back late to fish him out and toss him in the woods.
Mousetraps work GREAT and 99.999% of the time they work in the blink of an eye.
I feel pretty bad about it.