Picking up my chickens tomorrow. They will be about 20 weeks old and have been brought up on cracked corn and whatever they can find in the barnyard. They are not laying yet. I just bourght layer feed, and grit, oyster shell. They were in a "Petting farm". What should I expect in behavior, eating, and laying when I reduce the 5 of them to 45 sqft of run + 20 sqft of coop?