There were several reviews indicating these units did not work. Well, perhaps, you didn’t see the button under the unit where you have to turn it on, who knows.These exact units are used by the gardening professionals in my subdivision. I went to inspect where they had them set out among all sorts of flowering plants. I saw no deer or rabbit browsing on any of the plants, so I made sure this was the unit on amazon & ordered 8 of them. I live in Alabama & have deer morning, evening, & nighttime traveling through my yard eating all my plants, such as Azaleas, Lillies, Roses, & one buck even used one of my pink dogwoods I bought 2 years ago, for a rub & killed it along with breaking off several branches. Bought another one & first night got leaves eaten off it by the deer, not to mention several new azalea’s I put out at the same time.So, I installed the 8 units in almost all of my beds & guess what, I have not found a plant that has been touched, so I bought two more to strategically face to form a bit of a fence around the front yard.I have seen one dog travel through the yard, stopped & immediately retreated, then I have seen a cat wanting to poop in my new mulch I put out. The cat wen flat to the ground when the unit spotted it, then reversed direction & took off. I might mention last night before going to bed, I looked out into my yard & saw one of my units on. I couldn’t see what triggered it but it was probably lurking some tall shrub like trees near one of my azalea beds. Unit finally went off, so whatever it was, I suspect a deer, based on the late hour, so it must have run off.These are a godsend for my yard. Whoever makes these has introduced a great device, congratulations.Bob (Birmingham, AL)