[rufty]

Just sharing my confusion here.
So this weekend I moved the girls' coop and run closer to the house so that I it'll be easier for me in the winter weather and to give them a fresh bit of ground to play on. As part of this the run and coop got a full clean, disinfect and full fresh bedding and covering in the run. Restocked the tub that the dust bath is in too. Spick and span I thought for any rubbish weather to come.

So this morning imagine my concern when the least dominant bird has filthy feathers just under her wings. Encrusted with mud and the like. I checked carefully and I can't see any signs of mites or anything like that.
Now all the searches I have done talk about filthy or muddy bum feathers but I checked around her vent and it's fine, they're nice and clean, it's just the feathers underneath and below her wings that are mucky.
Now it could be that the girls are only just discovering dirt baths - the dominant two have only just taken to it over the last few days despite me trying to encourage them to do it for months. I was actually really pleased over the weekend when I saw them taking dust baths for the first time.
So it could just be that being the least dominant one she's only just figuring out what to do and it getting it slightly wrong. I did notice last week that she was acting weird with the bedding in the nest box and one night when I went to check on them I clearly disturbed her and she immediately started taking bits of bedding from the nest box and dropping onto the top of her wing (where it promptly fell off) and she then went and did it again.
All a bit strange. Especially since she normally doesn't like to be handled but this morning when I was checking her for any parasites around the mucky area she seemed quite keen on being handled which is a first. She'll normally wriggle and squirm, but today she was quite happy to be handled and inspected.

I had considered giving her a good dusting with diatom powder anyway just to give her a good clean; even if there aren't any mites it can't hurt, and if she is itchy it'd probably help.  On the other hand if there are mites and I just can't see them then it'd also be the right thing to do.
All that said it could just be that it's the co-incidence of the move together with her learning how to do dust baths that is causing the upset. I'll keep a close eye in case anything develops but as always open to suggestions.

[ghost61]

My hens throw bits of straw on their back when they are either about to lay or just after.  Plenty on these b about that behaviour, which seems to be normal.  I think your hen is taking a muddy dust bath, and the soil underneath the nice stuff you have put out has been discovered by her digging her bath.  Any signs of hollows in the run? Mine are sometimes quite dirty with soil, but then within a day they are nice and white again!

Hope all is ok though, and isn't it great to have them near for the winter 

[grinling]

mud could well be due to dustbathing. Dust the diatom anyway but also check for red mite by using white paper in various cracks and end of perches. I use Hillfooters slurry as seen on this website with good results.