I got two chicks from someone who couldn't care for them. They are approx. 5 weeks old. One is a regular sized chicken and the other is a bantam (the one with the issue). For the most part both chicks feathers are coming in quite well but the bantams chest is still down material and is very sparse and her skin almost seems raw. No blood... I'm 90% sure the chicks are the same age and the other one is not suffering the same problem. The bigger chick doesn't pick on the little one that I know of. I watch them quite often. Any help would be appreciated.