I bought one 4 or 5 years ago and have deployed it when possible ( about 20 % of the time when calling ) and I have yet to have it make a difference as far as a bull seeing it and coming in closer. I have had cows, deer etc see it & be close to it and was relieved it did not scare them. I still carry it as the one time it does work & keeps him coming , I will think it is the greatest. My problem has been getting it out fast & in the right place. Mike