Well well well... I found a yellow jacket nest this evening. They've been raising hell with the bees but I've been unable to locate any nests until this evening. I know there's more but... one at a time.
It's in kind of an awkward location in a rotten old retaining wall. It's not a good location for the "kill it with fire" technique. Too bad. I like the Kill It With Fire method.
I can shoot a can of poisonous liquid death in the hole. Not sure if that will get them or not. I've had mixed results doing that.
I'm thinking about trying the "glass jar" method of covering the hole with a clear glass bottle so they can't figure out how to escape but it's kind of an awkward place for that also. I might be able to shove the neck of a clear beer bottle in the hole and seal it with clay or mud.
Any other suggestions on how to exterminate them?