I've had three bping dogs. Lots of bag nights with and without them. Cannot say they deter or attract bears. I've heard both ways they can prevent a visit and some say will attract bears. My last dog, Pooch, a Yellow Lab X, barked at bears a couple times. Once at home to a bear tipping over my garbage can that was in the back of my truck, that I was taking to the transfer station the next day. The other time, in broad daylight, he growled while sitting next to me and I looked in the direction he was looking and a bear had come to the lake we were camped at and was walking along the outlet of the lake. Good doggie! I've never had issues with bears when out bping. I scare them up early mornings ususally and they take off, whether they have cubs or not. They can't pick out a standing figure, but if you shift your weight from foot to foot, they instantly zero in on you.