So I have 7 chickens that live in a 12x24ftx5ft high pen in a petting farm and I want to redo their pen to make it more fun for them/nice looking. Any ideas on what I could add to it? They have 2 little coops/houses, which I'm planning on replacing with some nesting boxes since the houses were originally built for baby goats. They also have 2 perches in the corners but they never sit on them. They'd rather sit on the roofs of the houses. The front half is rubber mats and the back half is dirt that I'm thinking of replacing with grass. Any ideas to add that are cheap???