Get a real cage... I sure hope you aren't keeping a ferret let alone more than one in a space that small, that'd be criminal.. Ferrets need a large amount of space. I had a pair in 4 foot tall 3 foot wide 2 feet deep cage, and it wasn't big enough. They're social animals curious to the point of accidental suicide. Not good pets, the kit I had died from an intestinal blockage from eating a rubber ball, the other one I had died of old age. I don't recommend them as pets, they're an incredible amount of work and they only live about 7 years.