I have 5-BR's that will be 13-weeks old on Wednesday. They reside in an Eglo Cube with a 6' run. They are fed quality crumbles for chicks. I clean the Cube daily & recently noticed a lot of small feathers about an inch long with an occassional large one and what looks like dandruff that blows out with the wind when I open the cube for cleaning. The feathers look to be too big to be pin feathers. All five appear healthy and greet me every morning when I let them out. This is my first time in raising chickiens and wonder is this normal or should I worry about the babies?