My four year old hen Susan has been seemingly less active within the past few weeks, and for the past few months, she has had a messy rear end, which seems to be getting worse--I honestly can't tell. I checked for fly strike, etc today, but could find nothing wrong. She sits on a roost a lot, but her eating habits are normal. I'm starting to suspect it is Susan who is laying the eggs that I find broken in the nestbox. Would this play a part? Is something actully wrong or is she just less active? Is this maybe because it is cold outside?