ANIMAL-TRAP
A falling door with teeth to strike the retreating animal.
The animal enters the cage and nibbles bait held on hooks fixed to a vertical rod. Moving or rotating the rod withdraws its horizontal terminal from a flange on the hinged front door, and the door falls. Spring catch members on the door pass the front of the trap and lock against its outer side. Teeth on the bottom and sides of the door strike any animal still in the doorway, preventing it from backing out.
“These teeth make it impossible for the animal to back out of the trap, and as his only course is to move inwardly, his capture is made certain.”— Theodore Vanderbilt Clapp, from the specification
And the world did not beat a path to his door.