I have 26 2wk old chicks. i put them in the coop at 5 days old. It is very secure and we check on them too much. They are growing like bad weeds. I noticed that they scratch their heads and pick at their feathers quite a bit. Is that normal or could they have lice or such? I'm new at raising chickens but I am really enjoying them so far. Oh, I have pine shavings in the coop.