SNARE TYPE ANIMAL TRAP
Requires the animal to place its head inside a wire noose.
Two arms joined by a heavy-duty spring are held closed against spring pressure by a trigger lever engaging a pivoting bail. A wire snare loop, connected to the trigger lever, is set in the animal's path. The animal enters the loop and pulls it, which pivots the lever and pushes the bail off its ledge. The spring forces the arms apart, tightening the loop around the animal's neck and pulling it against the arm.
“This, of course, pulls the snare loop tightly around the neck of the animal with considerable force and snaps the animal against the portion 15A thus killing it instantaneously.”— Kenneth G. Brownlie, from the specification
And the world did not beat a path to his door.