Almost no feathers on neck.

[jackei]

I am very worried. Today when I got home, I saw many feathers inside the chicken coop. Then I notice two of our five hens has almost no feathers on the necks. Attached close up pictures. Any ideas what happened? What should I do now, and to prevent it to happen again? Thank you very much,

 

[K R 2709]

Maybe they are moulting? Otherwise you may have another chicken pulling their feathers out. Hope that you find a out what it is and how to help them.
Best wishes