Horse Fly

Horse flies and deer flies are true flies of the family Tabanidae in the order Diptera, whose adults are often large and agile fliers. Females parasitize land vertebrates, including humans, biting them to obtain blood, and prefer sunlight over dark, shaded areas, being inactive at night. Found worldwide except for some islands and the polar regions, horse flies are sometimes called gadflies, a name also applied to the unrelated botflies, and contrary to popular belief they cannot see infrared light or otherwise detect heat at a distance.