Yes it is a pre-fab. It says it can hold 12-15 birds but I only have 6. I wanted to give them more room to avoid any problems. There is a 6''x6" window inside for ventilation but it faces the side of my garage. They are approx. 13 weeks old.
My coop has an enclosed run with a perch then an enclosed area with nesting boxes and perches that can be shut up. Metal pan below the perches for ease in cleaning. I have dry straw in this area although they are not laying yet. Why don't they go in there?
The few times I have put them in...