I own pygora goats and we have had problems with coyotes and wild dogs. I heard about the Nite Guard lights from other goat owners. The consensus was they seemed to work, so I tried some. Since then I have not seen ANY sign or tracks anywhere nearby. So I want several more for my guinea hen pen. I believe the lights also have a secondary effect – we live back off the road in WV and the blinking lights have even stopped a couple of uninvited human visitors as well.