I think I have battled them back to win or a temporary truce if the queen is still alive.
From my reading on the internet, most likely the wall nests, or underground nests, or cones from the eaves are yellow jackets, which seem to be an extreme problem country wide. The german yellow jacket seems to be taking over. Unlike a honey bee or bumble bee, the yellow jacket has an unbarbed stinger so it can get you over and over. They are also known to sting for the fun of it, at least for reasons other then defending the nest.
Especially liked the one entomology website that mentioned not to plug a wall hole until you are sure they are dead from poison as they can chew through the wallboard and be inside the house.
Am also glad I have left the big hanging melon in the tree that is a safe distance away. Supposedly those are a type of hornet, sometimes called a bald faced hornet I guess, that actually attack the yellow jackets.
Apparently as the german yellow jackets migrate west, the hospital visits are on the rise. One queen equals 3-5000 kids.
del