Out all morning today working on a Bruce Trail property, putting up a bit of fencing, with a bigger crew who were starting construction of a new side trail. The Black Flies were out in force, though they didn't bother me much at the time. Two hours later though, the bites had all turned red. Mrs. F.G. took one look at my arm and got one of those looks in her eyes! I just don't notice them biting, nor do they itch later, but I know they really bother some people.