We have a 20 foot by 21.5 foot fenced enclosure for the ducks to go in during the day and a pen in the garage at night. My house backs up to a cornfield so we get a lot of coyotes. Right now we have 2 pekins. How many more ducks can comfortably fit? I wanted to get 4 to 5 more but don't want to if it's going to overcrowd.