The entry door is spring loaded and held open by the split perch. The bird will land on the perch, releasing the spring loaded door. Watch the video with this in mind, and you can see the sequence.
Although the trap works on the ground, we recommend placing it high enough so that other predators cannot get to it. In my area we have feral cats, dogs, coyotes, foxes, skunks, weasels and other creatures that will approach the trap for the captured birds.
