Motion sensors have been a staple of home security systems for as long as such systems have existed. But they may not be the ideal choice for most homeowners.
First, motion sensors aren’t always completely reliable. They detect changes in infrared energy within their field of vision. Should someone wear clothing that shields their infrared energy, and/or if they move very slowly, they can defeat a motion sensor.
Motion sensors are also highly prone to false alarms. Any quick changes in sunlight within their field of view, for example, can trip them.
A second big issue with motion sensors is that they only work after the burglar is already inside your home. A better option is to use window sensors and glass break detectors on ALL windows in your house–in addition to door sensors, of course. That way if a burglar opens any door or window, or breaks any glass, the alarm will be tripped BEFORE they actually get inside your home.
Lastly, motion sensors leave one big hole in your home security system: they are not armed when you use the “Armed Stay” function. Of course they can’t be, otherwise you’d trip the alarm as you move about your house. But this means there’s a hole in your alarm coverage while you’re asleep at night.
Use window sensors and glass break detectors on all of your windows, and you’re completely covered, even while you sleep at night.