Blood-feeding dipterans can be classified based on which sexes feed on vertebrate blood and on food preference. In certain species of dipterans, only the females feed on vertebrate blood, which is required for egg laying; these species include black flies, sand flies, biting midges, mosquitoes, horse flies, and deer flies. In other species of blood-feeding dipterans, both male and female flies feed on vertebrate blood; these species include stable flies, horn flies, buffalo flies, tsetse flies, sheep keds, and hippoboscid or louse flies.
