Very true - separate the bully. I have a runt that was always being picked on, and I had no choice but to separate her. Tried and tried to reintroduce her once her foot healed, but no - she now lives in a very large rabbit cage, within the coop. I have a roo also that started getting picked on by the other roos, so he is now in with Angel. The rabbit cage has turned into my 'isolation' cage, per se - neither Angel nor Hawk bother anyone that needs to go in there for a spell. Worst comes to worst, you can always make a cage with hardware wire for any future isolation needs, but for now I would def use the dog crate, esp. if it is for larger dogs.