One of my 10 month olds looks like she has lost feathers on on her back end. How do you know if it is molting or something else? It's getting cold up here now. What season or month do they molt? At what age do they have there first molt? She seems happy and laying eggs. Don't see her getting picked on either. Any thoughts? Have been giving them Organic feed with "DE" in the mix....so I am not thinking mites???