Help! Hens missing feathers!

[Mcatmom]

Hello smart chicken people!
I’ve noticed that all my hens seem to have these bare spots on their backs, right above their tail feathers. Today I went in the run and noticed one looks really bad, seems to be missing the majority of her back feathers and there was some blood at the base of her tail feathers. All the hens have this same spot to some degree, some worse than others. Any idea what may be causing it? And also, how should I treat this/help them heal? Thanks in advance!

 

[sourland]

Do an on site search on Pin Less Peepers. A bird or birds in the flock are feather pecking/plucking. Generally it is the birds in most perfect feather.