Have had ongoing feather issues for several months now. Rooster's chest looks positively gnawed on; not bald but feathers are broken off and he looks almost sheared. Two hens have huge bald patches at the base of their tails, and one is way worse than the other. The poor "worse one" also has a bald bum and today I noticed that she is losing feathers on her neck. For about a month, she has looked mangy around her eyes and on her face - she is also shrinking in size and is thin. Now ANOTHER hen has the bald, red patch at the base of the tail. What gives? First I thought parasites, though I saw none - stripped the coop bare, sprayed insecticide (pyretherin or something like that), dusted with sevin and poultry dust, put all new bedding back in. Dusted all chickens with Sevin (several times at 2-3 week intervals). Have also sprayed them with Frontline spray and repeated this a few weeks later. See zero and have seen zero evidence of pests - I go out in the dark with a flashlight and roust everybody up for a look-see, but nothing. Out of a flock of nine, including roo, four have pretty bad feather loss, two have minimal if any feather loss and three have zero feather loss. If it was a parasite, wouldn't they all be affected? Should I worm them? How do you know if chickens have worms? They've never been wormed, though I put apple cider vinegar in their water. I've tried adding supplements to the feed (Kickin' Chicken) but then they don't eat it. I've tried adding vitamins/electrolytes to their water, and they won't drink it! I give them tons of BOSS, melons, fresh corn on the cob, yogurt and the high protein game bird/showbird feed as treats. They free range all day so overcrowding cannot be the issue. I've never seen anybody peck anybody else, though I've seen girls reach back and fuss with their bare spots themselves. Should I try saddles? I've put bag balm on the red spots but haven't yet sprayed them with Blue Kote. Should I Blue Kote them? Have also tried a no pick spray with aloe vera, but it's for parrots, not for chickens. I hate to spray anything on those red parts that might sting and both Blue Kote and Hot Pick seem sting-y; are they? Sorry for long post; at my wits' end and I think this one girl in particular (the mangey one) is looking really unsteady in general. Her eyes don't look right; she looks like she doesn't feel terribly well, but they are all still laying and running around and doing their thing. Thanks for any and all recommendations!