I am new to chickens. I have 10 of them and this is my first winter with them. 3 of them look like they have taken a shower and forgot to blowdry their feathers. They have matted looking feathers all down their backs. I picked one up and she isn't wet, just looks like it. What is this? They have an insulated, non heated coop and it hasn't been that cold here in Montana. It is 36 degrees now but has been in the 40s. Thanks.