One of our hens is limping and we noticed one of her nails is black. Could that be an injury or a fungus of some kind? Thank you. Also, Is this the time of year when laying either stops or slows down? Do we need to put a light in the coop or should we just let them be for the winter months. Our hens are 7 months old, this is their first laying season. And one more, I know the water needs a heater to keep from freezing, but does the coop need heat at all?