Our hens have no laid a single egg since the beginning of October. A few of them molted, but now everyone is fully feathered and looking healthy. There has been a supplemental light on in the coop consistently for at least 7 weeks from 2-7am. I have looked in the coop and run and see no evidence of eggshells or egg eating. Is there another reason that they would not lay? We have 12 layers and 2 pullets who are now around 25 weeks old. Help!