The Starbar Bite Free Stable Fly Trap is an easy-to-use fly trap that can control and catch thousands of nuisance stable flies. Flies are drawn to the trap when sunlight shines through its translucent surface. Place traps outdoors in sunny areas where flies tend to gather.  Once the trap is full of flies, simply toss it out. This trap is recommended to be used outdoors in areas such as around dairy barns, pig barns, horse barns, and chicken coops. The trap has a weatherproof adhesive surface that won't get washed away.