molting???

[Freerangeamy]

I have six chickens, and I have three loosing feathers on the back toward the tail. whats up? they are in a coop not free range , try to make them comfy, are they molting or is one picking on them?

 

[junebuggena]

Pictures? Could be a few possibilities. How big is the coop? How big is the run? What are they fed? Any roosters? Age?