we keep a few very small live traps (the cage kind with the door that closes when the little tray is moved as they start to eat) for the room where are rats are kept. Im not sure if they make them small enough for mice though). We use live traps incase its one of our breeders that gets out, because we wouldnt want to lose a mature breeder that way. Also alot safer on the toes as many people as there are working in that room.