Bala Subramanian Ram
I beg to differ.Good PIR sensors work only with living objects so paper should be out of the question. So far as birds are concerned, I guess there are few PIRs that are made immune to pets’ movements. Those can be used. Bur I wouldnt PIRs for outdoor purpose since light and heat from the sun can make the sensor behave in unwanted way as it is sensitive to temperature.
P.s. The house next to my office has PIRs installed above the compound gates. During office stays at night, the light is triggered annoyingly by dogs and cats.