there full grown or almost full grown and thats the smallest part of the cage it gets to about 4 ft wide the farther you go up I'm using a dog play pen with garden wire on top and I have a nesting box and I have hemp bedding
also its not there forever home its there winter home since I live in Canada its still cold ish here like -4c then I'll move them to a 130 square ft cage outside that I'm purchasing