ANIMAL TRAP
A mirror is provided to arouse the animal's fighting spirit.
The animal squeezes between two spring-loaded walls fitted with rearward-angled teeth, which permit entry but grip its pelt if it attempts to retreat. Opposite the entrance, a mirror mounted on the rear door is faintly illuminated by openings in the roof, while a second pair of openings lights the incoming animal so it sees its own reflection. The animal rushes at the reflection, steps on hinged trap doors in the floor, and drops through into a receptacle below. An artificial animal may also be secured to the rear wall as a further inducement.
“When the animal so sees its reflection in the mirror, its fighting spirit is at once aroused, it will then rush at this reflection, see the reflection rush at it, will forget all thoughts of caution, and will readily and blindly drop through the trap doors.”— Akos J. Hall, from the specification
And the world did not beat a path to his door.