This has a lot of room but is usually only used for new mommies and a hospital tank.
Three Level Ferret
Bar spacing is too wide for any rats but adult. However, the two full levels and third half "loft" level fit my two (neutered) boys and two girls very comfortably. Placemats work best for covering wire levels in this model. Ledge addition and closet shelf added. $100 @ Superpetz.
Mrs. Doyle and son, Dougal "Dumpling" Doyle; Bree; Sheriff Sampras Chechekevich