Zevo Flying Insect Trap uses light to continuously attract flying insects (house flies， fruit flies and gnats) and capture them on to an adhesive backing that you never have to touch without chemical insecticides， odors or messes!Replace refill cartridge when its full of insects. Check it every 15 days or as needed.KEEP ZEVO PLUGGED IN 24/7FOR BEST RESULTS:Place in electrical outlets that are easily accessible and near common areas.Use in an indoor electrical outlet where flying insects enter into the home such as garages and enclosed porches/patios (near entryways)， and where they tend to gather， such as in kitchens， near fruits and vegetables， trash cans， houseplants， drains， etc.Try other locations and electrical outlets if ZEVO is not attracting flying insects.Dont obstruct the trap or place behind doors， furniture， computers， TVs， etc.