The recommended coop space is 4 square feet per bird inside, and 10 squar feet per bird in a run. So, if you have a coop that's 16 square feet, if you were to follow the recommendations, you'd have room for 4 birds. When I am acclimating chickens to a new coop, I put them in it and leave them locked in for a week or so. I also have an attached run so they can go outside. I wouldn't leave them in a small coop for a week at a time because that can cause other behavioral issues.How big does a coop have to be or what can it be made out of (cheap ideas) and how do I get them to go into it.