Here is a cut-out I did a few years back from an abandoned house that the owner wanted to restore. The owner, who now lives in NJ, grew up in the house, and had let some relatives live in it and they ran it right into the ground. The owner wanted to restore it, but the contractor wouldn't start until the bees were gone. The owner claimed the bees had been there probably 30 years or so. I have heard similar exaggeration from other folks before, so I was a bit skeptical. When I got there, I could see propolised entrance holes in numerous places spanning about an 8ft x 8ft area. It seems like the bees started in the middle of the house and as time went along and comb became damage/destroyed/wore out, they kept progressing to the next cavity over. In the picture below, to the left of the window, you can see a dark spot which is a hole with propolis that I think may have been the original entrance. The area to the left and above the window was filled with remnants of abandon comb similar to the picture below. The bees where now occupying the the cavities on the end of building. The amount on debris that had decomposed over the years was up to a foot deep in some parts, and at the bottom of the active cavity the debris pile had what looked like meal worms living in it. There was also a ton of propolis everywhere, including an area of wax moth cocoons that where covered. One thing that I found surprising was the amount of varroa I saw on the bees, especially since it was so early in the season. There was only about a coffee can full of bees, and I saw 3 bees with mites on their back even though I wasn't looking for them. There was also a colony living in a big tree, about 25-30 feet from where this colony was. The owner said he saw them swarm from the house to the tree last summer. I trapped them out of the tree.