Here's what I believe to be the long and short of it: deer can hear ATV's. Whether they associate that with being fed, or with a day filled with gunshots, or just with some stinky human busting up in their living room - it all depends on what they experience when an atv encroaches on them.

My 85 year old grandfather rides an ATV on portions of my hunting land 12 months out of the year - feeding cows, checking fences, etc. I've been on stand and watched deer when he came through within hearing distance. From what I've seen, they pay attention, but it's not like they bolt for the next county.

That being said, I KNOW the deer can hear it and know that they associate it with some form of human prescence. Therefore, I minimize my ATV usage during hunting and drive as little as possible through my hunting areas during the season.

Last week, I parked in a clearing probably 1/2 mile from my stand during the pre-dawn hours. When I returned around noon, I eased up to the clearing and 2 does were feeding within about 40 yards of my atv. Obviously, the 4 wheeler itself didn't scare them.