ORIGINAL: madvilledoc

That is a louse fly (also called ked). Don't worry, it isn't a danger to people.

Medical and Veterinary Importance
No parasites, predators, or diseases have been described from the Neotropical deer ked on white tailed deer. They are not known to transmit any disease to deer or humans. Hunters dressing harvested deer are likely to encounter these flies and possibly may be bitten.