I have 15 ten week old chickens-- 13 pullets and 2 cockerels. In the last few day, I have been seeing increasing numbers of feathers in the pen. I dont mean one or two, we are talking hundreds. I see no signs of bald areas on the chickens, and sit next to the pen for 10-30 min a day and have not seen any picking. As I am new to chickens, I just want to make sure this is normal. They are all healthy, eating well, drinking well, and no sign of any abnormal poos, all solid brownish with occasional white. They are being fed grower pellets from S.S. and scratch with treats of watermelon, yogurt, lettuce or grass clippings. Also, no sign of mites that I can see.