Our Djungarian hamster has had a big, wooden house (under the wheel) where she used to happily live since we got her a few months ago. But recently she stopped using it for sleeping. Instead she just burrows under her water bottle and sleeps there, using the house only as food storage.
What could be possible reasons for this behavior? Could it be the house doesn't satisfy her needs for some reason any more?
The house has multiple compartments, separated by tiny walls with holes so that she can crawl between them:
We tried to remove the walls, just in case, but she didn't care at all for this change.