Bison dust bathing. When this picture was taken, I was on top of the camper (cab over type) and didn't have to worry about stickers getting in the way or getting stuck like I might if outside on the ground. Trampling isn't the way I want to leave the planet. By the way, bison are VERY noisy creatures... and they often drool... and have stringy stuff running from their noses. And they sure are cool to watch... as long as you don't get any on ya.