A good guard dog will alert us or our neighbors when an unfamiliar person enters the property. It is also a signal to a burglar to that he is unwelcome and unless they are willing to risk potential injuries and apprehension they should look elsewhere. Lighted accessible locations of the yard during night hours. Each exterior doorway should be lighted from dusk to dawn. Lighting can be equipped with timers or sensors to turn lights on at dusk.
Motion detector seem to work even better some can be equipped with a bell or other warning sounds.
Keep windows, entryways, driveways, walkways and porches clear of trees, bushes and flowers. Even though they may provide you with privacy they can also give a burglar a place to hide. Prune large trees. Tree limbs can provide access to 2nd story windows. Planting thorny bushes and shrubs near windows and along fences can also discourage burglars.