Moulting or Sick?

[toomanylayers]

My 18m old hybrid has got a bare chest, her three sisters are fine. I've seen the odd feather in the run/ coop but I don't think any of them have moulted yet. I'm still getting 4 eggs a day and she looks ok. Is she moulting? I haven't seen any bugs in the coop or nesting boxes but if I did wouldn't they all be affected? Rocky's had a bare chest for most of the summer and now I wonder if we should visit the vet. Advice please.

red mite and other bugs have been at their worst this year so even if you cant see anything then think you need to check it out with the vet otherwise your mind wont be at rest. thats what i would do anyway.

A bare chest for a long time but no other feather loss doesn't sound like moulting to me - when mine moulted it took each hen a couple of weeks.

Thanks for your comments. I took Rocky to the vets today. The vet said it was 'self mutilation' as she is stressed! The vet suggested separating her and gave us a cream for where her skin is red raw. The bare patch was the wrong place for mites (and I've seen no sign of them anywhere else). I haven't seen any of the others picking on her either. She's not stopped laying and has enough food and water. I have no idea how to get her to 'relax'!!