American Horse Fly
Horse fly is the most widely used English common name for members of the family Tabanidae. Apart from the common name “horse-flies”, broad categories of biting, bloodsucking Tabanidae are variously known as breeze flies, clegs, klegs, or clags, deer flies, gadflies, or zimbs.
Horse fly bites are painful, the bites of large specimens especially so. Most short tongued (short proboscid) species of horse flies use their knife-like mandibles to rip and/or slice flesh apart.
Horse fly bites are more immediately painful than that of its mosquito counterparts, although it still aims to escape before its victim responds. The flies are very agile and adept at flying. Their bites may become itchy, sometimes causing a large swelling afterward if not treated quickly.
They are often not deterred by attempts at swatting them away, and will persist in attacking, or even chase their intended target for a short time.
Adult horse flies feed on nectar and sometimes pollen. Females of most species are anautogenous, meaning they require a blood meal before they are able to reproduce effectively, if at all. Much like male mosquitoes, male Tabanidae are not ectoparasitic and lack the mouth parts (mandibles) that the females use in drawing the blood on which they feed. Most female horse flies feed on mammalian blood, but some species are known to feed on birds or reptiles. Some are said to attack amphibians as well.
Larval horse flies are predators of small invertebrates in moist environments, such as in mud on the edges of bodies of water, in damp soil, under stones, or in rotting logs.