How does it work? - One Stop Gardens 32-1/2 L x 10 W x 13-1/4 H Collapsible Medium Animal Trap

Put bait on the pan inside then on the side of the trap there is a trigger mechanism where one arm rest on another arm that holds the doors open. When the animal messes with the bait the 1st arm will move allowing the 2nd arm to fall closing the end doors.