This insect trap is engineered for 3-way protection. First, a UV fluorescent bulb generates a warm light, attracting insects. Then a second lure, an exclusive Ti02 titanium dioxide-coated surface, produces CO2 (the same gas we emit when we exhale) that's irresistible to mosquitoes. Third, a powerful, yet whisper quiet vacuum fan sucks insects into the retaining cage where they dehydrate and die. A unique twist-to-close feature ensures that any insects still alive in the retaining cage will not escape when the trap is turned off. Convenient for travel, RV's, patios and pantries, the Dynatrap® ultralight can be placed just about anywhere (use outdoors only in a covered, protected area, for example, a garage, screened-in porch or four seasons room).