I haven't noticed any false positives, though it IS very sensitive. So bugs flying near it (day or night) definitely trigger it to record. I think you can adjust the sensitivity, though I haven't played with it. You can also "blank" out areas of the camera view to ignore motion. For example, trees in view of one of my cameras move back and forth when it's windy and constantly trigger the motion. I was able to select the trees in the view and ignore motion there to solve that. I do not believe it uses thermal sensing for motion, but rather changes in the image it sees.