Sudden turn on head chicken...

[Chicks Galore3]

My top-of-the-order chicken, daffodil, has gone broody. Tonight I went to block the nesting boxes, so she couldn't access them. She was sitting outside the boxes in the broody hen posture, and the lowest chicken on the order pecked her quite hard in the face. No blood, thank goodness. Daffodil didn't do anything to her. Three more chickens did the same think, on the head and back. No feather pulling or blood drawing. Anyways, I took Daffodil out, just in case the pecking got worse. I figured out she can defend herself, she puffed up and chased a cat around the barn.

I put her in the 'infirmary', a little 3'x3' cage we built for things like this. So, do you think they are picking at her because she's broody, is she sick, ect. She was 'vibrating' earlier, which I asked about also-http://www.backyardchickens.com/t/727205/why-is-my-hen-vibrating

What are your thoughts?

 

[Animol]

Some of my hens "vibrate" when they go broody and feel under threat complete with puffed up feathers, also although my other chickens don't bother her on the nest when she goes off it for food the others seem to find it amusing to chase her around the back garden pecking at her though not hard enough to draw blood and she's the 2nd to top of the flock.
Yours probally didn't peck at her fellow chickens because she didn't think of them as a threat to any potential chicks where as the cat, being a predator is. If you keep her isolated for a little while with no eggs she'll go back to normal. If not then there must be another reason for her behaviour.

 

[ramirezframing]

I have never been able to break a broody. I have had silkies brood on nothing for 3 months straight. So anymore I don't even try. I just limit the eggs they get. But all of mine do the same as yours. Only one polish hen was on a serious attack mode, to the point that I couldn't even open the door to the coop without getting attacked by her. I hope she never goes broody again

 

[Chicks Galore3]

Ok, thanks guys! I have broken one broody before after about 1 1/2 weeks, and I just kept taking the eggs and shoving her out of the nesting box. This little moody broody I think will take awhile, she seems pretty dedicated!!!!