2 of my hens have a weird molt some people say it could be mites i have treated with one spot 4 times and it had done nothing the thing is i think that it could maybe be genetic because the only to birds in the loft with this problem are mother and daughter the mother is a 2001 bird and got yhis molt when she was 2 years old the daughter is a yearling and has only just got the molt this year she was fine as a youngbird here are some pics of them can any one help????