[NCHornet]

I think something as you describe would drive you nuts. My motion lights are constantly going off because of wind, dogs, deer etc... If I set the sensitivity any less it may to trip on a human. The driveway alarms work, and I have thought about getting one, but to be honest the above poster is right on, nothing better than an alert dog. I have a 100lb black lab, and although she is on her last couple years with bad hips she still alerts me whenever anyone is near the house.