Need advice bald chicken bums

[Amyandalan]

Im a new chicken owner so sorry if this is already covered. Have 4 chickens who 1 by 1 have become bald on their bottoms in a matter of days, no where else. All still eat, drink, lay eggs. Appear perfectly normal. Can't see mites but would mites just attack the bum? Is this normal moulting in winter? Help!

 

[TallChickMagnet]

Simple answer, yes...

 

[Smoochie]

Yes examine them for mites at night but if one by one they are bald it sounds like someone is picking them out. Feather picking is quite common. You need to pull up a chair and watch their behaviour.

 

[Amyandalan]

I observed them today and did see one hen feather picking two of the others. Oddly enough tho, it's the chicken at the bottom of the pecking order doing it. She is much bigger than the other 3 and the only chicken with almost all feathers. How do I stop her? Iv put in that stop pecking spray, iv sprayed the bald chicken skin with that violet spray to protect any wound and in the hope the purple may put her off. How long will it take for feathers to grow back?