I have three bushes with yellow jackets in them. The bushes are of the same type. My wife went to trim the bushes unknowing they were there and was stung several times. The nest are deep in the bush, you cannot see it. I spayed a wasp pesticide in the bush, they started to swarm out, I counted at least 30 and left. They were back the next day. Can youi tell me how to get rid of them, can you recommend a pesticide that will kill them and not the bushes?