I have a flock of 9 ,only one of which is a black silkie. She doesn't roost with the other girls even when she isn't broody. She used to buddy up with a too but he died a couple of months ago. She looks like she as raised scales with white crusty stuff underneath. I will post pics tomorrow. My question is, can only one in a flock have them, the others don't seem to have any. I was thinking that perhaps sleeping in the nesting boxes makes the birds susceptible ? I'd be grateful for any input. Thanks.