The ultraviolet light is supposed to attract mosquitoes against an electrified grid, which then zaps them. Well, it’s true that plenty of mosquitoes are attracted into your backyard by the light, but once the mosquitoes catch a whiff of you, they ignore the light completely.
First, it reduces ice formation within the mosquito’s cells, so that water hardens like glass but doesn’t form ice crystals that can then damage the cells.
What turns the mosquito on are goodies like carbon dioxide, heat, moisture, and lactic acid, which is secreted in sweat. These four elements make our bodies prime targets for the mosquito’s bite.