This one was the most difficult to find that I have ever had. The ceiling wouldn't give a heat signature. It was made of what looked like a laminated plaster board. Very thick and almost rang when you hit it. I drilled 11 holes in this ladies walls and ceiling to find the bees. They had come in on one corner of the living room and walked down the entire length of the room on the pressure band to the other corner of the room, roughly 15 feet. After finding them I was told by the owner that they had sealed up a hole just to the right of where I found them. As Homer Simpson Says "Dooooooohh!!!!!!"
I didn't post all the photos of the destruction. I'm ashamed to. http://picasaweb.google.com/rsderrick/RemovalFromOlderHome