We use a couple thermacell units. Been using them for the past 3 years. They do help clear most of the mosquitoes, from our experience. Sometimes we'd pull into a site and several mosquitoes would be there to greet us. We setup the 2 thermacells around our site, and a few minutes later, it's relative peace... We still come home with a few bites, but would probably be more if not for the units. We run them from just before dusk, until bedtime, and in the early morning hours if we're up. They work best in a wooded site with little-to-no wind. In a wide-open site or with a lot of wind, it's pretty useless....