I have 3 Khaki, 4 Welshes and 5 Ankona Hens. They all are about 8m old. They started laying eggs 1.5m ago. Every morning I would get 7-8 eggs. Then it dropped to 3-4 eggs every other day. Then, just only 1 egg a day. Lately, no eggs at all. What could keep them not laying eggs? Winter? They are on a high protein diet and they are free ranged. Any ideas?