Today's gardening news:
Yellow jackets make nests underground, with burrows to the surface, and they get really upset if you run a lawnmower over the burrow entrance.
No, I didn't know the hive was there. I learned about it the painful way. Now I seek revenge.
I know how to deal with such nests. I've done it before. It doesn't involve gasoline, parking a running lawnmower over it, flooding it, or any other "hold my beer" style attacks. Keep it simple and safe.
Go to the hardware/garden store and buy a container of powdered insecticide.
A few hours after sunset, well after the yellowjackets have gone to bed, go out and pour powdered insecticide into the burrow entrance. Fill it completely, and then some.
And you're done. The yellowjackets will try to burrow back out through the insecticide, and that will kill them.