layered effect

Make your home security system like an onion, not an egg. Layers upon layers are not only the best deterrent, but also the best defense against break-ins. Criminals can easily bypass a single line of defense, but multiple layers will slow them down and serve to alert you or your neighbors that someone is trying to break in. If enough of these deterrents are visible, most of the time the would-be intruder will simply choose to move on. A good example of a layered defense is holly bushes outside the window, double-locked, barred and safety-coated windows and something difficult to climb over inside under the window.