It is more often overcast and raining here in the winter and since I have my coop and run under a large oak tree that is taking it's good old time to shed it's leaves it is rather dark where my chickens are. I have my old, small run that has a wooden floor and is covered with straw for them to go in when it is very cold. It opens out into the new run. I was wondering if it would be beneficial to add a light that contains the same spectrum as sunlight that one can buy for retiles for my chickens. I am sure that the lack of vitamin D must have some effect on them. I do not intent to keep the light on for 14-16 hours to keep them laying I would prefer for them to rest during this time and besides I have 2 younger hens now 8 months that are laying so we have eggs.