Hi Taryn7,
I have heard of people getting their problem balls to eat rats by defrosting rats in chicken stock, also if you defrost them with a blow drier, never tried any of these on mine but hear they do work. I had the same problem with a mall ball and all I did was say if he is hungry he will eat and 9 months later he did! Don't worry people I monitored him closely and he never lost much weight in that time and is now at the 1.2kg mark!