[redreet]

We have had 8 black rocks for two years and for the last three or four months half of them have been losing their feathers from around their back and breast.  They look ok until they bend down and then they look rather sore and red raw.  It's a long time for a moult, isn't it?  And I have been using diatomaceous earth for red mite on a regular basis - on their sleeping quarters, not on them.  They eat well and lay well but rather worried about them.   RR

[helens-hens]

It would seem odd to me if they all moulted like this at the same time and in the same way. Have you checked them closely for any external parasites e.g. lice?

[joyfull]

also by using only diatom for the prevention of red-mite is not enough. You really need to use something like poultry shield as well - because you spray this on it can get into all the nooks and crannies better than a powder.

[Embeth]

One or two of my chucks are much the same. I suspect the red mite. I've just sprayed all the hen house and nest boxes with 'smite a mite', I'll let you know how they go on.

[moomintroll]

If you can't see any creepy crawlies on them, they still could have mites. You can get depluming mites which live inside the feather quills. Hope you get sorted 

[Sassy]

Check their quarters for red mite by using white paper and sliding it up and down in nooks and crannies - if it comes out red you have them.