I was using my Husqvarna 545FR forestry clearing saw with a string head clearing light brush and weeds along some trails on my property and hit a nest. Group wasps, meat bees, whatever they are.. little bastards nonetheless. At first there was one or two I saw through the metal screen face shield of my helmet and thought nothing of it.. then there were more. Fortunately there were not a lot. I started running up the short hill with the brush cutter still in harness. Even at my age it is amazing how fast you can run uphill carrying something like that when so highly motivated.. Got to the top, and still on the run shut the saw off, dropped it, and ran for the house. Got stung or bit (whatever they were doing) a couple of times and back in the house found another under my collar trying to get another bite in.
Another incident at my old tract home. Had a nest I did not know about. Set the hose-end sprinkler, turned it on, and they started flying out of the ground- about a dozen or so. It was a black vinyl hose with a yellow stripe. They were stinging the hose (assuming it was a snake). I turned off the water and froma distance I pulled the hose back. There were a couple with their stingers in the hose and they were flapping their wings frantically trying to pull their stingers out of the hose.