Was taking part in forest pathology seminar. Swung a Pulaski into a stump & instantly there was a cloud of the critters coming from somewhere near the stump, or maybe from the stump itself; I didn't stick around to find out. They didn't touch me even though it was a warm day & my face was just 3' from the stump when they launched.
Ripping out some blackberries one day 10 yrs ago, I backed the old JD over a nest. Was a cool day & I was being just as dumb as they were. Here they were flying all around me & I stop the tractor, shut it off, lower the cultivator to the ground, then I took off running--right over the nest. They didn't get me that time, either.
A few weeks ago I was covering a slash pile with plastic so I could burn it this fall after the rains come. Climbed up on the pile to spread the plastic, noticed a couple YJ's flying around about the time I got stung. Then I saw a lot more. Turned out I was standing right by the nest. I was just as afraid of falling & breaking a leg while scrambling off the pile as I was about getting stung some more. Got to the ground, rushed to the house, had my wife check me over & she found half a dozen more on my clothes.
A week later, I was dragging the cultivator along the fire line to improve it & ran over a nest. Didn't see anything until I was coming back for a second pass & saw the cloud 50 ft. in front of me.
Had a lot more encounters over the years; the most that got me at any one time was 3 or 4.
I put my traps out every spring & catch the queens & that really cuts down on the number of nests around here. Caught about 50 queens this spring and there were another 50 or so in the wood pile that didn't make it thru the winter. I might bait my traps this fall to catch this year's new queens. Haven't tried that strategy yet.