After looking up more pictures and descriptions and getting more dead ones I am leaning toward yellow jackets or paper wasps. they look more like the but act like paper wasps. I dunno. We will continue attacking them.
They look like yellow jackets. Same ones that will use/build burrows in the ground. They like wall cavities, especially ones filled with cellulose (like mine), or empty ones. I've never had a nest active a second year, but I've had them in the same house just in a new spot. I wish I had a solution for you. I think the size of their colony affetcs their aggression (safety in numbers). I had a big colony in the front corner of my house one year and set up a bug zapper on a pulley suspended from the soffit and got it right in front of their entrance, then pizzed them off. They attacked the plugged in and on bug zapper. I was never able to clean the zapper of wedged in carcasses, they were packed in quite tight. I've tried blocking their entrance hole, but they just chew a new one. Sevin does work if you can get it into / close enough to the nest. A bit easier with ground nests.
That's interesting... I've never ever heard of YJ in walls/building.. But the cold/frozen ground makes sense... I've also never heard of them NOT attacking...
I recently learned a new trick for yellow jackets. Sticky traps. Get the big ones and place near nest entrance. When one gets stuck it will emit pheromones that will draw others. Looked to be effective.
I am not 100% sure. Lemmie see if I can find my source....nope. Lost to internet oblivion. They looked like what you'd think...little white tray with yellow sticky stuff. Guessing dimensions were around 4-5x8". Looked like this one...sortof. Edges were smooth on one I saw loaded with wasps. I mentioned it because you may be able to easily stick on up there with some 100mph tape or something. Chemical warfare is not super advisable when dealing with the home space IMO. Also Backwoods...last year I tested a harnet spray on a nest in the pole building. All I had to do was thouroghly blast the entrance hole of the nest once and it wiped them out. The name of the spray is Bee Bopper. We have sold it for decades at my workplace. Ohio Power Co. was the customer who used to buy pallets of the stuff. It doesn't foam or anything and doesn't smell too good, BUT it will literally knock them out of the air if contacted and from my own test will subdue a nest via fumes or incidental contact. Sorry you have to deal with them. It's bad enough when you find a nest in the yard, let alone in a wall.
