18 billion flies can't be wrong, according to the Flies Be Gone people. Flies Be Gone is a highly successful and non-toxic method of controlling flies. While only about the size of a football, it can catch up to 20,000 flies thus effectively eliminating flies within a range of about 100 yards for up to 6 weeks. Simply unfold the bag, pour in the powdered, non-toxic bait and water, place the cover, and hang in a well-ventilated location away from full or direct sunlight. Practical, disposable, maintenance-free and environmentally safe.