I have two girls-a buff cochin and a plymouth barred rock. They will be about old enough to lay eggs within the next month or so. They have a large coop and a nest box that they both sleep in at night. Do I need to build another box so they have their own space? They eat well and spend most of everyday out of their coop in our lower yard---I know I need to feed them a different diet once they start laying--is that correct? Someone has suggested that I put a ceramic egg in the nest box.