+1 to Dan. I have heard people having good success with scenting the rat with mouse bedding or even a mouse itself. Yes it can live off mice alone but when she gets really big you are going to have to be feeding 4+ mice in a sitting instead of 1 large prey item. The only time any of my animals gets a mouse is when I don't have a rat small enough on feeding day. (and that is for my young babies I recently got) Good luck!!