Hmm... Maybe I just got lucky, Daniel. All I know is that the problem got solved. The area surrounding their known entry hole was pretty much open lawn. I didn't recall having seen any yellow jackets congregating in other nearby places at the time, unless a second entrance was more than 50-or-so feet away.
They certainly are nasty little creatures, though. Depending on any future homes they might set up, I might try your method next time --- if I can get up the courage, that is.
Thanks, Daniel.
Kat
