My wife saw a large rat outside out house in AZ and we started hearing scratching on the roof. Then we found a nest near her car battery when she went in for an oil change. I didn't want the rat to start damaging stuff so we decided to get a trap and try to kill it. One morning I put 4 of these in my front yard and baited them with peanut butter. When I came home from work I checked my traps. The good news is I killed the rat. I also killed the cutest baby chipmunk I'd ever seen, a bird was nearly decapitated, and a giant squirrel had dragged the trap all over the yard before dying a terrible death. As a killing machine this trap gets 5 stars but I won't buy one ever again. I'm going to try to find a non-lethal trap the next time I want to get rid of a critter.