ANIMAL TRAP
A humane trap that breaks the animal's neck and back.
The user presses the handle rearwardly and downwardly with one hand until an extension on the trigger plate catches in an opening near the handle's end, holding the spring under tension. Bait is placed on a pointed member on the trigger plate. When the mouse steps on the trigger plate to reach the bait, the engaging member clears the opening and the coil spring snaps the movable jaw closed. The toothed flanges of the jaw come down across the animal's neck and back.
“It will be noted that we have provided a humane animal trap by so constructing and arranging the parts, that the neck and back of the animal will be caught, so that the neck and back will be broken and the animal paralyzed, so that death will practically be instantaneous.”— James A. Mertz, from the specification
And the world did not beat a path to their door.