Living in the Pinebarrens of NJ, we are exposed to a whole lot of deer. In all my years of looking at them, hunting them, and having to endure their antics during the rut season, I can tell you that they are the type of animal that gets used to anything. I honestly believe that you could pass a herd of deer grazing and sound an air horn, and while they might scatter the first few times, after a while, they will just ignore it. While these deer warning devices have their place, they don't take the place of riding with extreme caution when you are in heavily populated deer areas. Keep your eyes glancing towards the side of the road, and remember, with does, where there is one, there is sure to be a few more. That is, when a doe bolts across the road, be ready for all of her girlfriends to follow within a few seconds....