I have six laying hens. They have been laying for about two months now. They eat layer pellets daily and oyster shell is supplied constantly in a separate feeder. I also give them veggies or cracked corn three or four days a week as a treat. For the last three days I have gotten four eggs a day. Three of them are fine but one of them breaks when I wash it. With only slight pressure from my finger. I have no idea which hen it is and all of them are acting normal. Any advice? Thanks in advance for any ideas.