Pullet Lost Feathers Around Vent - Please Help

[ChattyChickens4Life]

My Easter Egger pullet, Muffin, has lost a bunch of feathers around her vent. The skin isn't red, bleeding, or irritated since I last checked. She is still laying daily and seems active and healthy. She eats and drinks fine, as well as devouring the treats I give her. She is not lowest in the pecking order as we have 2 silkies, one of which we introduced when the original pullets were about 3 months old. I will post a picture when I go down to check on her, but for now, does anyone have any ideas of what could be going on? If you need any more information, let me know and I will give it to you! Thanks so much!

- Chatty

 

[ChattyChickens4Life]

Here are some photos of her vent. Thanks in advance for the help!!!

 

[ChattyChickens4Life]

I believe the feathers are being pulled by the others because she is higher on the pecking order - they are challenging her in some way? How should I go about stopping this behavior? I'm not sure which chicken(s) are doing this.