Temperature will drop to 4 degC tonight and one of my chooks was attacked by a roaming pair of dogs and lost half her feathers. I have solved the problem by loading steaming composting grass into their sleeping house and putting a layer of polystyrene foam waste on the roof. So insulation plus under-floor heating. The compost will generate heat for three days. One other chook hasn't come home so I don't know if she is dead or just hiding. Have dropped flyers around the area with a phone number.