Stable flies, horseflies, deerflies, horn flies, and face flies are a menace to your horse's health and well-being. Common feeding sites include the lower legs, flanks, belly, under the jaw, and at the junction of the neck and the chest. When stable flies have finished feeding, they seek shelter to rest and digest. The bite of a blood-sucking fly is painful and some horses have such a low fly tolerance that they can be driven into a snorting and striking frenzy or an injurious stampede. Even fairly tough horses, subjected to a large number of aggressive stable flies, might spend the entire day stomping alternate legs which can cause damaging concussion to legs, joints, and hooves, and result in loose shoes, and loss of weight and condition.
Stable flies breed in decaying organic matter.
Moist manure is a perfect medium. The life cycle is 21 to 25 days from egg to adult. A female often lays twenty batches of eggs during her thirty day life span. Each batch contains between 40-80 eggs. When the eggs hatch, the adult flies emerge ready to breed.