My ferrets are housed in a 2 story Ferret Nation cage. It's quite spacey and they love it. I would NEVER let them have free roam as they can be destructive (they love to dig and if you give them large space, they will not potty in designated areas). Mine are let out quite often to play with each other, and I have some toys for them and a maze they enjoy. Currently my oldest ferret is very sick (likely Adrenal Disease), and it is going to cost a lot of money to get her fixed up.