ANIMAL-TRAP.
The bait itself is a load-bearing structural component.
Two hinged jaws are spread apart by pulling the finger pieces at the rear, which tensions a coil spring around the pivot. As the jaws separate, a two-part trigger mechanism swings upright on its own and passes through an opening in the movable jaw. A piece of bait is thrust between the trigger's diverging members, wedging them apart so a shoulder stays hooked under the jaw and holds the trap open. The mouse removes the bait; the two trigger members swing into alignment, the shoulder disengages, and the spring snaps the jaws closed.
“The bait, therefore, constitutes a means for maintaining the member 8 engaged with the jaw 2, to hold the jaw 2 open, and, at the same time, the members 7 and 8 coöperate to grip the bait 18, so that the bait cannot become dislodged accidentally.”— Henry Heald May, from the specification
And the world did not beat a path to his door.