Bald baby society finches

Question
Hi.  I have a total of 7 finches; 5 zebra and 2 society.  The societies had a clutch of 5 & 3 survived (2 were pushed out & though I tried to save them just couldn't).  I had them all together & then noticed the zebras were pecking out the babies' feathers!!  I separated the societys from the zebras and thought things were going well.....BUT, 2 of the 3 are bald & there are bald spots on the "runt's" side!!! I got some skin & plumage drops and put them in the food.  Yesterday I got some "Avian Solution Daily Bath Spray" that is supposed to stop plucking.  I've been watching them today and all 3 of the babies, but mostly the runt, are picking at themselves.  Like they are itching.  I cannot find anything online to help with this!!  The books I have don't really say anything either.  WHAT CAN I DO?  What can I get to help them??  The parents still feed them, and they have actually started to try and eat on their own.  The were born 10/11 so they are about 4+ weeks old right now.  They fledged a little over a week ago.  Thank you!!!!

Answer
It could be feather mites (finchfaqs.webs.com will explain what those are) and the treatment is quite simple. I personally use Avian Insect Liquidator (A.I.L.) which can be bought from ladygouldianfinch.com. Just make sure you FOLLOW THE DIRECTIONS EXACTLY. While it is harmless (best to shield head from spray though), improper mixing can make finches sick. The owner of the site is also highly knowledgeable of her products so don't be afraid to ask questions if you have concerns.