Have a tiny bantam chick. She is about 10 days old. I thought she was about the same size as the others when she hatched, but now she is defiantly smaller. She is always getting under the other chicks to stay warm. She tries to get under their wings. She is feathering out fine but is always cold. The others are fine & never appear cool. Should I put a warmer bulb in, I switched to a smaller bulb a week ago since the others were getting hot.