I found this on one of my Serama Roo's that we have had for about a month that we got from a very reputable breeder. When we got him I noticed it and I treated him because I thought it was lice, the hen he came with, and my entire flock with Ivermectin. Its now been a month and he still has these at the base of his feathers. He is in a cage with 2 hens and neither of them have this. Any ideas? He is supposed to go to fair the 2nd week of August but he wont be able to if this doesn't go away. Notice on this one there are little nodes coming off his skin almost in place of feathers.