My female heart rat Trank for as long as I have had her (I picked her out of her litter mates as soon as they showed markings and shes almost a year old now) has always curled up in those food crocks u can attach to the cage. It doesnt matter if its the small size or the large size, if its full or needs to be filled she is in the dish just chillin. Its pretty darn cute. Does anyone else have rats that think their food crocks are lounge chairs? Now mind you I do have hammocks and igloos and such available to her...she just prefers her crock.