We have 4 chickens. 2 red sex-links and 2 golden comets. They are 16 weeks old. We have 3 nesting boxes in their coop. I'm concerned because they go to sleep every night in their boxes. Is this normal? They free range all day then at about 8:00 every night they go put themselves to bed in their boxes. We put plastic eggs in there, but all we find is a lot of poop in the boxes each day!! Will they lay eggs there since they sleep there? What do we do? We got the chicks at just a couple days old, and this is our first time raising chickens! Help!!