Deer flies are particularly bad this year and questions pertaining to treatment methods have been asked. The best way residents can combat biting flies is when outside in an environment where they tend to gather (i.e. parks, wooded areas, beaches, marshland, etc.) is to wear long sleeve shirts, pants and a hat (avoid darker colors especially blue, it attracts them) and utilize repellents (preferably DEET based). If you cannot wear long clothing, use repellent and avoid significant movement, this is a key way of attracting flies. The deer flies will reduce in number as the summer moves in, allowing some relief.