I just got my coop finished, it is 4x4 feet on the inside and have space for a heat lamp. My chicks are 4 weeks old. Highs this week are 55-73 and lows are 36-52. I have 3 autralorps and 3 red producers. They have been in a plastic bin in the house with a 120W bulb the last few weeks, last night I moved them to the garage with the 250W heat lamp. I would love to move them to the coop with the lamp this week during the day and bring them to the garage at night. I put them out a few hours yesterday and they seemed happy with all the room to move and things to explore and jump on. I brought them in when I noticed they were all huddled under the light. Is this an OK plan? When can I move them outside and leave them at all night?