I have wasps in a loft over an extension, I have no access to. I can see where they are going in and out of the eaves. If I fill this hole would it be a good idea or not.
I had this problem and got pest control to deal with it. The wasps nest was in the eaves and they were managing to find their way into my house. The nest was sprayed and I havent been bothered with them again and that was a couple of years ago.