I have 7 chickens who were all laying in October. Five of them are under one year and two are just over two years old. They all stopped laying except the Welsummer. She lays nearly every day but not a single egg from the rest in 2-months. One lady went through a molt but he rest look shiny and fat. They get free choice feed, Fresh water, and greens from our kitchen scraps. What's the deal?