State-of-the-art smart electronics control this unique device. When a mouse enters the electronic mouse killer and negotiates its way towards the bait, it reaches a point where it touches both killing plates and completes an electrical circuit, which kills the mouse virtually instantly. Four AA-size batteries (not included) provide enough power for up to 50 kills. Warning light signals when batteries need replacing. Built-in safety features ensure that the Mouse Killer does not present a hazard to children or pets. A warning light signals when the device has been activated so that the remains can be removed and the trap reset. Full instructions for use provided.