Is this caused by mites/lice?

[juleeque]

chick is 3 weeks old, none of the other chicks have this. Is this lice?mites? or ???

 

[Firekin1]

Just looks like they're losing their down...some chicks lose it differently than others when their juvenile feathers start growing in, sometimes it's pulled out by other chicks. If they had mites or lice all chicks in the area would be affected and you would see them crawling around on them.