Mites, Lice, or New Feathers Growing In?

[cluckbealady]

Help! I have a black copper Maran chick (5 weeks) who is smaller than all the others and has a progressing loss of down feathers on its neck. It eats well and drinks, but prefers to stay under the heat of the brooder plate. I've seen it itching it's neck which made me think it could be mites or lice, but none of the other chicks have the same symptoms. Any thoughts? Thanks

 

[aart]

Are the other chicks pecking at it?
How many chicks in how big a brooder(inches by inches or feet by feet)?
If it is smaller and isolating, it may be ill.

 

[cluckbealady]

Right now there are 15 chicks in a 3x4 brooder. My next best option is to move their heat plates outside with them to their own transitional coop I am setting up today. I think they'll be a lot happier, despite seeming fine anyhow. The other chicks are not pecking my at it or showing any aggression toward the little runt.... he just makes do my standing on the feeder to eat since he is so much shorter than everyone else. He doesn't appear ill at all, he just prefers to stay under the warmth of the heating plate.