Hi All, Our 6 week old chicks are now in their coop and loving their run. I've removed their heat lamp and replaced it w/ a 40 watt bulb and they are doing fine. Soon the nights will be warm enough that no light / heat needed at all. I've heard that some people still like to have a dim light on all night long -- is this necessary / advisable or can they be left in the dark for the night? Thanks!