My girls are 1 1/2 years old and recently all three of them have stopped laying eggs all together. Nothing has changed in their diet (they still eat a layer feed and get oyster shell and chicken grit) and also get scratch corn as a treat. They are free range. Iv looked all over the yard for a hidden nest and have found none. One of them is loosing feathers, so maybe molting? Help I dont know what to do!