I have a question on motion sensors that I am not sure about. Most motions are rated for a mounting height of like 5-8 feet, few go to 9,10 or 12. What would happen if you mount a motion rated at 7.5-9 feet at 10 feet? Would it just cover as much distance? Would it mess up the pet alley? I need to mount a couple at 10 feet and would like to go with the 9 foot rated ones, I can live with less coverage but did not want to mess up anything else to cause more falses or kill the pet portion.