And black flies do frenzy. A black fly attack is a crime of passion. By comparison, mosquitoes attack coolly, calmly, with premeditation and an almost surgical precision. In chivalric tradition, they send defiance with their whine. They let you feel their bite and give you an honest chance to retaliate with a well-timed swat.
Black flies blunder blindly along en masse, silently, stealthily.
They crassly gnaw a hole in your skin and sneak off, leaving the blood flowing. Mosquito bites itch for a couple of days. Black flies raise welts that itch for a month. They'll make you crazy. Well, that was what we were up against.