So, my girls started laying and I am getting 2-3 eggs a day but I am concerned at the number of cracked shells. None have been completely broken and the membrane has been in tact but I am wondering if there is something I should be doing to prevent these small cracks. They are eating a layer pellet and I keep some oyster shell available to them. The shells are thick, much thicker than grocery store eggs. Does anyone know why this is happening?