I got stung last Sunday by them (3 times). Was fine that day/eve. By Tue it started to itch like a mosquito bite. Today is Thur and all good. I have been stung many times, very strange.I finally got the wood shed all filled with 3 cords, all ready to burn. All went well until I went to dump a wheelbarrow full of splitter trash on the burn pile. Yellow jackets had made a nest right where I dumped. They weren't happy about that. I got stung by a few of them. First time that has happened in years.