My chicks are 4 weeks old today. My BR, Buff Orps and silkies seem to be feathering out very well. Most of the RIR peanuts are feathering out good. Roosters so seem to be slower than the pullets. But I have this one RIR that still, after 4 weeks has only wing feathers and little tuffs around neck. The rest of him is all streached chick fluff that he is out growing. He eats and drinks, seems healthy. What is up? He is very strange looking. Like he is out growing his chick fluff.