I have four hens, one over three years old, and the others about 1 1/2 years. All have been good layers, though Sally (the old one) is slowing down. About 5 days ago, I found a shell-less egg. I’d heard of these and figured it was Sally getting old. Today I cracked open an egg laid two days ago (from one of the other hens; they lay brown eggs) and there was no yolk! What’s the deal? They get layer feed, kitchen scraps, a little scratch, a few dried mealworms each day. Good water. Am I missing something? Is this just Fall behavior (maybe they are going into molt already?) should I even be concerned?