How Humane Traps Work

A humane mouse trap usually features a small door that closes behind the mouse when it steps onto a small see-saw arrangement, at which point the mouse can only move forward into the trap. The following animation illustrates this:

Entering from the left, the mouse only has to crawl a short way up the ramp before the see-saw tips, which levers a small door into place to cut off escape. Since the mouse cannot go back it continues into the trap until it steps off the see-saw, at which point gravity resets both moving parts to their original position.

The simplicity of the design means that no power is required to spring the trap, and that once a mouse gets far enough to tilt the see-saw, it is highly unlikely that it will be able to escape. Because the trap resets to it's original position once the mouse has entered, it is possible for further mice to enter the trap afterwards.

To entice the mouse into the trap, there are usually holes around the edge to allow the smell of the bait to escape, as well as allowing any captured mice to breathe.