I think it depends on what deer you are hunting. Immature deer are lots more careless and may adapt to the intrusions. It also depends on where the atv's are ridden. Its one thing if you're driving across fields, but if you are driving through the woods including core areas you might as well forget ever patterning a mature whitetail who probably knows what it means when people start tromping through the woods on atvs in the fall. I myself won't take any risks when it comes to exit and entry and it usually gets me within bowrange of at least a couple of mature deer each season.