Light traps, or electric "bug zappers," kill mosquitoes, along with gnats, flies, and other small insects, but there is no scientific evidence that these devices reduce the number of mosquitoes in an area or that they reduce the chance of getting bitten. Evidence proves that they do more harm to beneficial insects than to mosquitoes and because light traps can draw mosquitoes into an area, they can potentially bring the bugs closer to people rather than repelling them.