My family used to have a cat which liked to play with the mice, but not kill them. One day I caught her playing with one in the garage, soon we were infested with mice. So I setup the ultimate mousetrap. You need a five gallon bucket, a 2x4, pill bottle, wire coat hanger, peanut butter and some water. Drill a hole in the center of the top and bottom of the pill bottle, straighten out the coat hanger and thread it through the pill bottle. You want the pill bottle to spin freely. Hook the hanger across the top of the bucket so the pill bottle is centered. I wrapped the hanger around the bucket handle where it attaches to the bucket. Pour several inches of water into the bucket. Smear the peanut butter on the pill bottle, put the bucket near infested area, and lean 2x4 on bucket as a ramp.
I did this in my garage, nothing for 3-4 days. Then one morning there were 13 mice in the bucket. No sign of mice since that time.