What bedding would be best for the babies? I heard that the grey fluffy kind could be harmful and that the pellets stick to their skin. Should I use some sort of fabric?

I find a towel, laid flat on the surface, and then covered with soft fabric strips like fleece and flannelette, is really good. It provides a warm, soft nest for her and the babies. She can use the strips to cover them and keep them warm. It's also a lot cheaper than most commercial brands of recycled paper. :)

Rat lover