This looks a bit … direct, but it dates from 1882. James Williams needed a device that would destroy a burrowing animal and give an alarm so that it could be reset. His solution was a revolver attached to a treadle. Touché.
The patent abstract adds, “This invention may also be used in connection with a door or window, so as to kill any person or thing opening the door or window to which it is attached.” Evidently Williams had bigger problems than rodents.
