I don't get it. Last night was my chicks' first night in the coop. They are 3 1/2 weeks old. They have 6 inches of bedding and a heater. It got down to 54 in the coop, but was over 80 under the heater. They didn't sleep under the heater. WHY??? Instead, they huddled in a corner by the pop door, which had very little shavings and was cold. WHY DIDN'T THEY SLEEP UNDER THE HEATER??? And what should I do now??? They seem fine this morning, but they should be freezing.