One of my 3 chickens is losing lots of feathers, especially around her neck and rump. Does not appear that the others are pecking at her. Because of the feather loss, she looks very skinny, but I know she is eating. Heard I can dust her for mites, since this may just be her first "molting" of her life. Any advice would be most appreciated. The weather here is in the teens and I know shes got to be cold, even though she's got a snuggly coop with lots of bedding around her. Thanks!