In thick cover the ones that scent you from downwind, you'll never see. Being scent free along with good camo and quiet stand habits will just get them closer. Remember the whitetails nose is it's first line on defense. On the subject of odor, human odor including mouth odor is very offensive to them, we smell like predators. Other odors,smoke,gas etc,are foreign to them but may be associated with humans or not depending on their experience with these odors.