Thanks BL (if I could be so informal). It's possible she's just molting. This is her first summer as an adult (and conicidentally our first summer as chook owners) so we may be getting alarmed about nothing.
She's not broody at the moment but neither is she laying and overall she just doesn't...
Hopefully this isn't too bad and fingers crossed, someone can give us some peace of mind. Our lovely natured light sussex has lost most of the feathers on her chest. They're strewn across all parts of our back yard.
I've checked for mites and I can't see anything but the exposed flesh (which...