Hang or stand the trap in outdoor areas such as gardens, patios and refuse areas. These reusable bottles include super effective fly attractant, flies can get in but they can't get out. For outdoor use, attracts flies up to... This twinpack of Zero In Fly Catcher includes super-effective soluable fly attractant which lures flies from us to 10m. Reusable, these fly catchers contain a non-toxic food grade ingredients attractant. Bait refill available separately.