That explains why they, like Fire Ants, also sting simultaneously.
Maybe if you get stung by only one, they sting isn't so bad, but when 5-10 get you at the same time, that crap is something you will always remember.
I thought the yellow jackets lost their stinger when they sting??? Am I thinking of another stinging insect? I seem to recall having to pull the stingers out, and even after the insect had flown away, the singer still had some muscle attached and would be pulsating the venom into my body.