Inside the rescue! disposable fly trap is a bait that flies find irresistible. This attractant is comprised of food and feed ingredients, and other food flavorings generally recognized as safe. The attractant dissolves and activates when water is added to the bag. Lured by the scent, flies enter the trap through the yellow top cap and  drown in the water. Disposable fly trap is intended for use outdoors. It will help control flies outside and keep them from getting indoors. We recommend hanging the trap around 20 ft away from any outdoor living spaces. Complete with fast acting attractant. Just add water to activate. Never touch the bait or flies. Disposable when full. Catches up to 20000 flies. Once lured inside the trap, the flies cannot escape and drown in the water added to the bag. Suggested locations for the trap include - near a dog run or kennel, In a barn with good air ventilation, around poultry, hogs, sheep, dairy and beef cattle areas, near garbage bins or dumpsters, near a compost pile, near a campsite. For house flies, false stable flies, blow flies, blue and green bottle flies, flesh flies, face flies and many others.