I love that... "mean-spirited" Has anyone ever seen "easy going, pacifist" black flies? The ones you describe in the Smokies sound like they are cousins of the ones we encounter in northern New England. Small enough to find a gap in whatever clothing/netting system you have, and travelling in swarms, they have a blood sucking attack that can turn a grown man to tears. I won't be surprised if Jack Bauer uses them on tonights final episode of 24 to break a terrorist down...