I think my chickens have mites. In the past two days, I've noticed that they are losing feathers in odd places - both sides of the neck, front of the neck, and saddle area (which although common, is odd for mine). This is very new - they've always been fine. I did add 3 large bags of mulched up leaves about two weeks ago to their pine shavings, which is why I'm guessing mites. What do I need to do - get everything out and bleach it?