I discovered a few of our chickens had mites a while back. I went and got a big ol bag of DE and have been using it in their coops since then. One Silkie seemed to been infested with it the most. I checked 3 out of the 4 Silkies I have. One of them was our Splash Silkie. He was the one that had them the worst. So the two others looked clean. When I got to "Splash" I discovered something new. I discovered a white looking build up on the bottom part of his feathers closest to his vent. That is where I check to find mites. When I saw this I kinda freaked out. Without a picture what do you think it could be? Is it possible to have on bird have it and not the others? Is it treatable? How would I treat it? I am trying to rehome these guys. I can't give anyone a bird with problems. http://ucanr.org/freepubs/docs/8162.pdf I went to this website. I hope the link works. On the second page there are pictures. The picture on the right looks almost exactly what I saw. Thanks.