The Hopkins Deer Alert DOES make deer look at your car. I tested it by driving near a city park where deer were calmly browsing, their heads down. I pulled up, waited a few moments, flipped the switch, and within a couple seconds all 5 deer lifted their heads and looked directly at me perhaps 75 yards away. I have not so far seen deer "running away" when they hear the chirping of this device. Today there were two deer on the side of the road as I approached at about 60mph. I saw them raise their heads and watch me drive by. So I don't expect this device to SCARE or REPEL deer, but I believe it does get their ATTENTION which in many cases may help avoid a collision. I suspect the effectiveness of this device is diminished on very windy days or in especially noise environments, and if you come over a hill and deer are right there in the middle of the road, you're probably still going to have an incident as they wouldn't have time to hear the chirping and react. But I believe this device will help reduce the risk of car-deer collision.