I have hunted with the Thermacell for 3 years now. The first year (before I had the holster for it) I accidently kicked it out of the stand. There is laid on the ground at the base of my tree still going. I had a doe and fawn come in 15 yds downwind and never winded me or it. I believe in them. I would venture to say that they would smell you and associate human odor (probably breath) to danger before they would stomp and blow because of the thermacell scent. Just my humble opinion. I will continue to use my thermacell and have had great results. More chance of them seeing me swat skeeters than bust and run b/c of the thermacell odor.

Kent