I have found these two years now on my old, wooden fence. They seem to appear (in Northern MN) by late June, and were swarmed around my fence for awhile. They seem to have disbursed a bit, but seem to be staying on old, unpainted wood. When I get close to them or try and touch them they jump (maybe fly?) away. Have seen them in several areas, all on old, unpainted wood. Found them late afternoon/early evening, but not sure that they aren't there at other times.