Yellow Jackets I presume? Those things are nasty buggers. Once when I was working for the Fish and Boat Commission it was my turn to stay back and mow the lawn at the office. The office is just an old house in the middle of the Delaware Watergap National Rec. area. It has a huge yard and our riding mower was broken, so I had to use a push mower. We knew it was basically an all day chore without the riding mower, so that person would always stay behind and work from the office all day mowing parts of the lawn at a time.
Anyway, everyone left to do field work and I got started mowing. Not too far in I ran over a yellow jacket nest with the mower and all hell broke loose. I had yellow jackets in my shirt and crawling up my pants. I ran inside, torn off my clothes and swatted them all off. The thing is, I did this without even thinking. Had everyone else still been there, I would have done the same thing. I'm glad they all had left. I ended up with like 20 or 30 stings.
I went in the basement later and found a can of longshot bee killer. I sniped the nest from a window like 30 feet away
I really don't think it had any effect, but I emptied the whole can.