lol its easier then all this
take a piece of string and tap it above your door make sure it falls on the inside when you leave then if they come in it will fall on the outside
also put a /stuff animal something small and moveable if the door is opened it will move the object
buy a deer camera :P set it up in your room facing the door any movement triggers the camera check its usb drive when you get home
[You must be logged in to view images. Log in or Register.]