We have a beautiful coop and 7 three week old chicks. I divided the coop with a wooden wall to limit the chicks to about a 45" x 32"area.....about a half of the coop's length. They have a heat lamp to keep them warm. Is there a rule of thumb as to how much space is good for them? They are healthy and curious and I thought maybe giving them another foot or so of length might help aclimate them for when they get the entire coop area. Thoughts?