Hello! I have a 12x8x8 aviary with a pair of wonderful Mandarin ducks in it. I was hoping to add to it but I am not sure if it is too small of an area to add anything or what lives well with the ducks. Any opinions or thoughts on what I should look into? We do get snow and are in zone 6b so our average lowest weather at any one point is -5. but usually in the teens and 20s in the winter. Thank you for your help!