I have now had Gretta for roughly a 1 year now and she is beginning to do something that she has never done before. She is constantly digging. She moves all of bedding out of a corner in her habitat and then climbs into the hole that she makes. And no matter what I do, she will not leave her hole, not even for food. This may be nothing but she is on her 5th day of not eating and I am beginning to get concerned. There have not been any changes in her surroundings either. Any ideas?