I have a hen pulling feathers

[RNT chickens]

I have a barred rock hen that keeps pulling feathers out my other hens and eats them.
why has she started doing this?

 

[sourland]

It can be dietary (low protein), but generally it is a result of boredom that escalates into a bad habit. It frequently starts this time of year when weather constraints require the flock to be penned up in the coop.