I think it depends on the person. I am not usually bothered by mosquitos here in New England, which can be FIERCE to some people, nor am I bothered in Belize. I can get away with Deep Woods Off (25-30% deet) and not get bitten at all. I usually go with something even lighter when in San Pedro if there is a nice breeze. My husband on the other hand has to use a stronger insect repellant, to keep the bugs away both in Belize and here at home. He says it's because I have bitter blood...LOL!