You will find people that say, " buy christmas lights, they are the same thing", they are not. Nite Guard is a L.E.D., not an incandescent bulb. It flashes more like a predators eyes. We have had trouble with coons and coyotes, major trouble. We have trapped, shot and defended against these predators, and nothing protected our chickens until we purchased Nite Guard. If you follow the manufacturers recomendations, for example, you have to place one unit on all four sides of your chickens, and at the same height as the eyes of the predators you are dealing with, you will not have any more problems. Granted, they are somewhat expensive, but well worth it. Also, the customer service with the company is exceptional. Just be sure that you place the units so that they have plenty of sunshine during the day and they will function without issues.