Make sure that all exterior single-swing wooden doors are of solid-core or paneled construction, with a minimum thickness of 1-3/4 inches. Install a wide-angle (180 degree) peephole. The peephole will let you see who is at the door without them seeing you or having to open the door. Hinges should be located on the inside of your house or have non-removable pins. Exterior sliding glass patio doors can be pulled up in their tracks making the locks useless. One way to prevent this is to install a few sheet-metal screws in the top track with their heads nearly touching the top of the door when it is closed.