i have a mini duna that i have used as a hospital cage for rats that isnt being used. i still have the platform and bridge, i wont use the wheel it comes with as i have a silent spinner. im thinking of getting some robos, i know they like to live in groups, but how many females would be alright in a mini duna cage. i already have loads of toys i can use in their cage as i have owned mice before. i was thinking 3 robos, but wondered what other hamster owners thought.