Also... Your hens may be stressed. Give them plenty heat in the winter and perches all year round. As long as they can escape a rude hen... They can handle themselves and heal.
I'm not sure what the poster means by "Give them plenty heat in the winter" but hens can tolerate the cold very well as long as they don't get wet or have draughts. Heaters in the coop are dangerous on two levels.... 1. they pose a fire risk and 2. If they fail ie power outage, the birds have become used to them and struggle to keep warm without them. The most important issue in winter s good ventilation at roof height so that warm damp air can escape, otherwise it can condense on the roof and drip back down on the chickens making them wet. Insulation under a tin roof will also help prevent condensation forming, but ventilation is essential.
I just wanted to clarify that with the OP being new to chickens and perhaps thinking a heater was necessary.