I have eight 10 day old Rhode Island Reds and ten 3 day old Barred Rocks. My brooder is 2 feet by 4 feet. I've got them separated with 1/2 inch hardware cloth dividing the brooder into two compartments. Is this necessary for chicks? When can I pull out the divider? The 3 day old Barred Rocks are really going to town in there scratching up a storm (they crack me up). They make the Reds seem pretty sedate!