Add water to the trap if the solution gets below the fill line. Water is needed to drown the trapped flies. Flies like heat, light, low wind. Place traps in sunny areas. If in an enclosed area such as a barn, place traps within 6 feet of an electrical light.
Flies search low for food sources.
Traps are most effective when placed 24 inches or less from ground level. Flies remain dormant until their body temperature reaches approximately 65 degrees F. Do not expect much activity below this temperature. Traps are re-usable. Replacements baits are available. Bait is also reusable for a period of time.