BTW, just a thought... my canaries have to have total darkness in order to stay healthy. Too much or too little light out of season really does mess up thier body chemistry. I cover the cage all but one corner- kind of a 5 minute warning... they know to find thier roost... they usually are ahead of me, as they can tell it is getting less light outside. Then I cover them all the way.... just thinking that your hens will do just as well in the dark...