Dandruff like specks on chickens

[AJJJ]

My chicks are one month old today. I see dandruff like white specks on them. One of them tries as if sand bathing. What does that mean. They are newspaper bedding right now. Are they itching, do I need to do something or give them diamatocous or sand w/diamatocous eartn so that they can clean themselves? Need help.

 

[Egghead_Jr]

Chicks are growing fast and constantly molting creating massive amounts of dander. It's all normal. If they are almost feathered now it's about time to think of getting them outside. Ween them from heat then put them out in coop and run.