Is there a rooster? Do these chickens free range at all? I am asking because baldness on the back very often means the hen is very much liked and is "over-used". If there are no roosters and you are taking care of mites, etc., it sounds like a boredom problem.

We use Diatomaceous Earth to take care of mites and also put it in the feed. We also use it for our cats and dogs. Ours free-range so don't have the boredom problem. There are two hens, however (out of 35) that seem to have great sex hormones and the roosters love them to the point of taking out their back feathers. They are totally free, so it seems they can escape if they don't like it!!!

What carmen said...

I'd add to check to see if they are eating the feathers they are pulling. If so, this could indicate a protein deficiency.

I'd attack this problem in several ways, all at once. Add more protein to their diet--scrambled eggs, cooked ground beef, live mealworms, etc. Fight overcrowding by making sure they have LOTS of room to free range and get away from bullies. Isolate the one hen until her feathers grow back if need be. Fight boredom by offering entertainment by food--raw corn on the cob, head of cabbage on a string, etc. These take time to eat and direct pecking AWAY from flockmates. If you notice dry skin, extreme preening or scratching, add a capsule of human vitamin E (poke a hole in one end of the capsule and squeeze it into their mouth) once a week for a while to add more oil to their diet. Don't rub ito into their skin if you can avoid it, as you don't want to soil the feathers or cause chilling.

Feather picking is a nasty habit that often develops from one of these causes and can be a very hard habit to break. I have a chicken info site here that may offer more help:

http://home.earthlink.net/~velvetsparrow/VSChick.htm

Velvet ~:>

Thanks for the information. I have isolated her. I put her in a wire cage within the big cage. There is no rooster now but there was when this started. they do not get to free range, but I am able to move their cage often to keep green grass under them as there isn't a bottom in their cage.They do eat the feathers sometimes but not always so I will add protein to their diet. I gave them corn on the cob but they weren't very interested, I'll try the cabbage.
Thanks again
Bev

Not interested in corn on the cob?! Those aren't real chickens, good heavens! :0 Try scoring a few of the kernels to give them the idea that this is something yummy, they'll catch on. Mine go hog wild for corn on the cob...

Good luck with them, I've had feather pickers before so I know what a pain it is. :)

Velvet ~:>