I think baschlais meant that the FN/CN is like a dollhouse because it's so fun to rearrange things and decorate for our rats aka "dolls"
I did have a huge dollhouse that I picked up at Goodwill and was going to make it into a cage or enclosed play area for my hamster but it didn't work out, it was wooden and would have soaked up urine and we couldn't find a waterproof paint or sealer that was non-toxic, water based, etc. The idea though, if we had been able to find a safe paint/sealer, was to use plexiglass with lots of breathing holes drilled into it to close up the main opening in the doll house and the windows. It would have had terrible ventilation and I'm sure the wood would have been quickly chewed through, so the idea was dropped though we could have probably found a safe sealer eventually. It was a cute idea, but not really functional.
