I have probably 100 hens, lots of food and water, about 8 roosters, about 45 nesting boxes and yes, some chickens are moulting, some are two or three years old BUT we've been getting about 20 eggs a day when it was hot. And NOW the average is about 12. I can't afford to have this many hens not laying. A few weeks off (aka summer vacation) was fine, but this has gone on too long. No, I haven't wormed them recently (because we eat the eggs). Any thoughts about why they are simply not laying?