New hen violently gatekeeping the coop and food

[Lyris]

I recently rescued four hens that were abandoned. Due to necessity they share a converted shed with my existing flock. Three of the four hens have had no problem since there is a ton of space. The fourth hen on the other hand... She's a bully. It started with her going after my broody hen whenever she snuck in. Then it spread to booting out the other hens in that nesting box. It's now gotten to the point where she patrols the coop in the morning and attacks everyone who comes by, including my rooster. (She's actually gone after my rooster several times - they're both torn to shreds from it. She hasn't done it lately though) My rooster is incredibly docile and isn't stopping her so she's getting worse. She guards it for *hours* until she lays an egg, then goes to guard the food dish. I have several feed stations and she will go back and forth guarding them when I refill them. If I try to give them treats she attacks everyone no matter how far the treats are spread. She stalks me around the yard so nobody else can be social with me. She settles down once she gets what she wants, but it's not fun for anyone else.
She's an incredibly sweet hen to humans, just not chickens who aren't part of her flock. I can pick her up and she immediately goes to sleep. Can you teach a chicken to not be so bossy? Can I do anything to keep her from gatekeeping the shed? How about treats? I already have a specific hen who gets treats first so her bullying everyone isn't great. Would Peepers help? Once her and her flock are healthy again I'd like to rehome them, but until then they've got to get along with my flock somehow.

 

[thecatumbrella]

I just rehomed a bully last weekend. She spent two weeks living alongside her former flock in my isolation pen. If I didn't have that, I would have crated her in a safe/shaded part of the run. They really do need to be with others, even if they're crazy, but I would not allow her to terrorize everyone. Sometimes a week or two in jail can reform them (especially if she has to sit there and watch other chickens eating from the feeders, but can't act on her impulses), though I wouldn't count on it. Like you said, she's a rehome anyway.