It's ok for 3 reasons.
1. You aren't Buddhist
2. We have dominion
3. God forgives you
Plus those filthy things murdered 250 million Europeans, what goes around comes around
Poor Mickey...
Heh. When I was newly married and we didn't own a cat we had a mouse problem. Did manage to catch it and we set it free in a field. However, wouldn't have a problem with killing it especially if it was destroying property or just on the possibility it was carrying disease.
To date, I've never had a problem with an invasive cow, chicken, pig, deer, or fish.
A couple of friends of mine have a cabin in the woods. One afternoon we were there and I noticed a mouse running along the floor. I commented on it, and my friend's wife freaked out. So he and I had the job of rounding up the mouse and getting rid of it. Once it hid behind the box of firewood it was just a matter of time - we ended up putting plastic cups at either end. Before long it was in a cup, so it was caught. I took it to the other side of the stream and released it again. For days afterwards I wondered what would have happened if I'd taken it home and let our cat meet a real mouse. He's an indoor cat, so probably never seen a real mouse before, but from the way he chases things and attacks toys he obviously knows how to hunt, even if only in theory.