We don't know anybody who has much use for flies, other than the creatures that eat them. There are many products at Gregg Farm Services designed to control flies on livestock: insecticide ear tags, pour-ons, insect growth regulators (IGRs) mineral supplements, oil slicks and insecticide sprays. 

Livestock producers know that Horn fly pressures of more than 200 flies per animal can result in up to a quart of blood loss, reduced grazing activity and an increased risk of anaplasmosis. All these symptoms result in lower weight gains and lost revenue. Come talk to Terry or Billy if you're puzzling about the best approach to livestock fly control. 

For your home or barn, your  first defense for fly control is to eliminate breeding grounds. Adult flies need a place to lay their eggs, and a clean home or yard just won't appeal to a mama fly. Clean up all animal feces promptly. 

Long-term insecticides are applied to areas in which flies tend to congregate, i.e., around feeders, water, stables, etc. Fogs and mists are intended for daily use. 

Sticky fly paper does work, and is most useful for low, indoor fly population. Commercially available fly traps work well for house flies, too. Traps usually contain some kind of food bait, sometimes in combination with a pheromone. Place fly traps where you see the most flies. 

Scrape your plates or other leftovers into an old Walmart bag, tie the bag shut, and put it in a garbage can with a tight fighting lid. If you save kitchen scraps for your compost heap, add sawdust to your bin to help absorb moisture and odors that might attract flies. Turn your compost pile regularly, and don't put meat or animal waste in your compost bin.