I have 4 week old chickens that lived in my kitchen until today. We moved them out the their "coop" which is a non-insulated shed. They have a 10x10 space with food and water. In the corner my husband put our big dog cage bottom and attached their heat lamp but he is letting them go all over the coop. If they can get to a heat source will they? Or should we force them to stay toward one side at night until they are bigger. It is still dropping into the 30s. I just don't want them to get to cold. He says they will use the heat source if they need it.