Fly traps, which can be made at home or bought in a store, are intended to lure the fly into a food source and trap and kill it. The bait for fly traps must be moist and can vary from a piece of raw meat soaked in water or beer to an old piece of fruit, such as a banana. Molasses and cornmeal mixed together also works well as fly bait.
Fly insecticides use chemicals used to kill flies and typically come in granular form. The following two common fly insecticides have three ingredients, each with a different purpose. The attractant is the "bait" for the fly. SNIP's ingredients: active ingredient: azamethiphos, 1 percent; attractant: 9-tricosene, .02 percent; and inert ingredient, 98.98 percent. Apache's ingredients: active ingredient: methomyl, 1 percent; attractant: 9-tricosene, .02 percent; and inert ingredient, 98.98 percent.
Flypaper comes in long strips that you roll out and attach to areas where flies are likely to fly into the paper and get stuck. The paper is scented to bait the flies and is typically made out of a combination of resins, castor oil and wax. Some fly strips will contain arsenic to kill the flies faster, but if it says "non-toxic" on the label, then it will just be the glue that kills the fly.
Fly traps that use Ultraviolet light to attract flies are often referred to as "bug zappers." This is because the UV light that attracts the fly is surrounded by a wire screen that is electrified. When the fly goes toward the light source and lands on the grid, it receives a high-voltage electric charge that kills it. The downside of this form of fly bait is that it doesn't target flies specifically and can kill beneficial bugs.