Mouse trap: a 5 gallon bucket with two inches of water in the bottom, a diving board that pivots so that when they go out to see what is at the end of the diving board, they fall in... Bread crumbs work pretty well for tricking them into using the diving board. We used to kill rats this way but used a 55 gallon drum with a little grain in the bottom and a 4x4 to smash them in the bottom of the barrel. Life on the farm.