OK - so my 8 barred rocks are starting to lay, but for this past week or so some one is breaking an/her egg in the nest box. Then this morning, DH let the girls out and turned to check the boxes and when he turned around, there was a egg right outside the coop, broken. It wasn't eaten at all, just broken. Could one of the girls be laying very fragile shells? I thought that eggs were designed to be strong, on the whole. And the color of the shell seems to point to the same girl, since we get a variety of shades of brown. Any ideas on what to do? I've got oyster shell out, free choice, though the feed I have doesn't include it.