Is it possible for only one chicken to have scaly leg mites?

[chick-george]

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.

 

[Cowgirl71]

I bought 25 hens from a friend last year and mixed them in with my flock. One of the RSLs had scaley leg mites. It was too late to save her when I noticed it a week later. I got really alarmed when I read about how contagious it is, but none of my other hens ever got it... Maybe I just got lucky.