I've recently been on holiday for 2 week, my friend has just been feeding/watering/locking up my small flock, they are free range chickens and have acres of land to run around on with my horses, my due to the wet winter my fields have been muddy, my 2 silkie hens went broody a week before my holiday and are still broody, they have lost a lot of weight but apparently this is normal when they're broody, they barely ever come off the nest to eat/drink...they don't even have eggs under them, anyway I pulled them out the nest box to do a quick health check, I do this every so often on all my chickens, and I noticed they have a thick build up of white scaly thing, not sure how to describe it, and both my silkie hens had this, none of my other chickens, I'm wondering if it's because I've not cleaned out my nest boxes or shed for a bit due to holidays and weather-.- I feel bad encase it's my fault! What do I do? How do I get rid of it? What is it? What's the best stuff to use on the floor in my shed and nest boxes? I need a lot of help and advise about anything and everything please, I'm kinda new at chickens! I tried to take a good photo but she was going crazy!