It's crazy how fast they can build a ground nest. I'm siding a house and last week my helper got nailed in the cheek by a yellow jacket. Gas down the hole took care of that nest which was on the back side of the house. Yesterday I was working on the front side and almost stumbled into another nest of the nasty buggers. Funny thing is, I was working in the same area on the front on Friday and they weren't there, Monday morning there were hundreds of them. Heading there before daylight to give them a 89 octane shower.