So far they have been tested in my apartment in S Asia where I have a lot of mosquitoes during this season. They seem to work. I haven't had any bites on my legs. I really like the color and they style and fabric. I just think the small is a bit big on me in the hip area. I am a petitie 5'1, 120 pound female. They are baggy on my bottom area. The length works well even though I am short. They cover my entire leg and I don't have to bunch them up on the length or hem them. So if you are taller, they may be shorter on you. I think if they had an XS size it would of fit better. Since I will be wearing in the apt to loung in and occasionally to hike in outdoors I think this fit will work although slightly bigger on me than I would like. So far they have been worth the price.