» This article's about the insect. For the band, see The Horse Flies. Insects in the order Diptera, family Tabanidae, are commonly called horse flies, and sometimes also forest flies or deer flies. The former, however, can also refer to Hippoboscidae, and the latter refers specifically to the horse-fly genus Chrysops. Often considered pests for the bites that many inflict, they're among the world's largest true flies. They're known to be extremely noisy during flight. They're also important pol… (More on Horse-fly)