I have 10 hens and live in southern NV -- daytime temps around 105 F recently. We had been getting 5-7 eggs a day, but for the last 2 days I haven't found ANY eggs. My hens do free range, but there's really nowhere for them to hide eggs. They've never laid anywhere but the nest boxes in the past. I don't think they're molting, but they've never molted before so I'm not sure. They're 15 months old. What could cause them all to stop laying?