darkness

Dears all, For the first time, finally my young pullet (5 months old) went broody. I have placed 9 fresh eggs of her and another young pullet (the oldest egg laid 5 days ago), she is on them since Friday (3 days ago). But I am afraid of the egg size which is a little bit small. Will the eggs be...

Now that the temp is below 10 degrees (and regularly below 0), I have put a light in the coop for some heat. I keep it on from dusk to dawn. However, I worry about the chickens not having any darkness. So, the question is which is more important? warmth below 10 degrees or darkness (having a...