I was wondering about this too. Shelley, our new girl, is spending most of the day dug under and does not seem interested in being under the lamp, while Tula, our male, heads right for it in the morning. This is her first winter with us. I also never saw her eating until I started taking him out of the enclosure to give her space. I think she is not thrilled with having him bug her all the time. We took her in because we thought she was probably unhappy in her previous home, but not sure how much she is enjoying the company!