I was watching my ladies via closed circute tv and heard a strange noise coming from one of the hens. It sounded like snoring / purring. Is this normal? I am so confused as to some of the noises they make. It has just started to get cold here and I want to make sure that they are not in distress. They have a nice coop to live in (so I think). And I'm not sure if why they are making this noise.