We have one of our hens that started laying wrinkled eggs and they are sometimes a bit non-symetrical. Started when she resumed laying this spring. I haven't singled out the offending hen yet. We get several a week from her. They look fine inside although we usually feed these to our dog. We feed a 16% layer pellets. They get grit and oyster shell regularly. They free range in a 20 x 65 run and also have access to our entire backyard until the garden is fully planted. Any ideas?