) Hi bugman!
I live in West Michigan and just before it is going to rain the flies start to bite! Can you tell me why they do this? It is even worse if you are out on Lake Michigan?
Probably the increased humidity makes them more active. Usually the female fly bites and often she must have blood before she can lay fertile eggs. My guess is the conditions are right for mating and the flies are biting as part of the mating ritual.