I'm using a couple of Home Depot's motion-triggered 500w halogen floods to illuminate the field for my critter cams, but have been having trouble with the motion sensors - especially in cold weather months. I tried substituting one of these: RAB Lighting SMS500 Mini Sensor, 180 Degrees Detection Pattern, 500W Power, 120V, Bronze Color: Job Site And Security Lighting: Amazon.com: Industrial & Scientific, but no improvement. They tend to come on for no apparent reason and stay on.... and no amount of adjustment/tuning remedies it. Been fooling around with a Raspberry Pi for heating/cooling a backup server in my garden shed - where the critter cams also live.... and I am thinking about hooking up a motion sensor to the Pi and having it turn the lights on/off. But I have no clue about motion sensors. For the one in the link above (about sixty bucks!) they do not seem to specify the type of sensing. ..... OTOH when I Google for Pi projects around motion sensing, the term "PIR" (Passive Infra-Red) almost always comes up - and those things are really cheap. The Question: Is PIR bottom-of-the-line, top-of-the-line, or what?.... the requirement is to detect small animals like foxes, raccoons, 'possums, dogs, cats, and so-forth after dark with minimal false alarms due to shrubbery moving in the wind and so-forth. The critter cams have constant IR until they detect the greater illumination of the 500w floods... but that could be turned off if it's a show-stopper. Recommendations type-wise?