Excaliber wrote:powerful (250 - 500W) motion activated halogen floodlights mounted out of reach from the ground and aimed at the major entry points (doors and low windows). There is a surprise and deterrent effect when the light comes on, and it provides you with some notice as well. You'll have to be prepared to become familiar with the habits of your local populations of armadillos, opossums, rabbits, etc. because these will trip the sensors if the high sensitivity settings are used, but the lights also produce a "deer in the headlights" response from intruders.
What I'd like to find is a few reasonably priced sets where the lights and sensor can be separated by at least 8-10ft. When you put the lights high up, the sensor has to be aimed down at such an angle that you can't simply avoid the low-lying animals. With a sensor at knee level, aimed and masked to ignore anything lower, you'll pick up humans while ignoring pets and most wild animals. Besides, it can be more effective to have several lights come on in different locations at once; it looks a lot less automated.