" I had a subterranean nest of them in the front yard and had to get rid of them to mow the lawn. "

Yep... me too... I was mowing and they came swarming out to 'defend' their hole. A couple got me. If they'd just waited, I'd have mowed and let 'em alone.....but NOW I was as mad as they were. Got my can of "nasty bug killer", turned it to 'stream', sneaked up and filled the entrance for 6-7 seconds, then ran... I had to do it a 2nd time a couple weeks later. Now I mow in peace.

The worst sting I ever got was from a dead one! Had an old, misbehaving air conditioner in the attic which was leaking some water, and I had the cover off, and was feeling around to see if I could determine where it needed sealing... when WHAM! I had hit a dead yellow-jacket right on the business end! Hand throbbed for hours....