First a quick background so I can explain the situation properly: I'm new in the chicken-world. I have ten pullets, they made five weeks old today (Wednesday Oct 10). I had them in a brooder in my garage for the first 3 1/2 weeks then moved them outside into their coop with attached run. I am in Hawaii, so it's warm. I don't know the night time temperature but I think it's safe to say that its never below 65 degrees. Now my situation / question: Until this week, at dusk they've "cried" - chirped loudly and incessantly - until I turned on the heat lamp (just a 115w brooder lamp) and then the little chickies would waddle their way up the ramp to their coop. Well this week I thought they might be tough enough to handle the night without the lamp so I didn't turn it on. The chickies cried for a few minutes and then went quiet so I assumed they made their way upstairs and that all was well. I checked on them three hours later and they were all huddled up together under their coop (in their run) in the corner asleep. The last three nights it's been like this so I turn on the lamp and then they march right up. To me it seems that common sense would make them at least go to where it's warmer (in their coop) and protected from the wind. Question: Should they still be on heat at night or should they learn on their own to sleep in their warmer coop without the lamp? Any opinions, knowledge, experience, etc, will be appreciated!