Re: bees in the wall
I had a wasp's nest hanging from the inside of the roof of my house. My Dad placed a bucket of water underneath it and hit the nest with a big stick.
It dropped in the water, and he covered it with a lid. Job done!
Another time in the same house, I had a wasp's nest underneath my bath, accessed via a gap in the wall where the drain exited. I had to get the pros in for that one.