In order to make a door alarm out of a mouse trap, you will need the following materials: a mouse trap, a clamp, 2 screws, caps, a piece of string, scissors, a screw driver, a drill bit, a hex-head screw, an a piece of aluminum from a soda pop can.
Drill a hole in the mousetrap at the point where the spring hits, when it snaps. Secure the striker with a clamp. Cut a piece of aluminum, and cut 2 slits in it. Remove the excess. It should look like a tiny T.
Make a hole in the aluminum for the screw. Fold both sides up. Screw the aluminum piece into the hole on your trap. Cut off 2-4 caps. Place the caps into the cap holder. Fold the aluminum over it.
Tie a trap string to the trap and connect it to the door. Make the string long enough to allow for your hand.