I posted an issue a while back about a white leghorn I had that died suddenly, spitting up a bunch of blood. One thing that might have been an overlooked symptom was the fact that right before she died, I noticed her neck was missing a bunch of feathers on the back of her neck. I didn't think this was related to her spitting up blood, dismissed this as molting or something. Anyway, now the other white leghorn I have has lost the feathers around HER neck as well. Here’s what I discovered.. 1) Quills are still in the bird, but it appears that the outside feathers were picked off by fellow chickens? Although I haven’t witnessed this, all my (five) chickens get along fabulously. This happened very rapidly in both cases, like within two days. 2) It appears the same thing might be happening under the wing.. in which case other birds are definitely not pecking the feathers away there. 3) I inspected, and didn’t see mites, but I concede that doesn’t mean the mites aren’t there. (see pics) 4) the other four birds I have seem like they’re in perfect health. I cleaned and shop-vac’d my entire nesting areas and replaced the pine shavings. I made sure that some diatomaceous earth was mixed in with their feed just in case of mites, and applied a bit of the stuff to the chicken as well, thinking it wouldn’t hurt. Does any of the pictures look familiar?