[R_A_W]

I have 2 hens, Dolly and Mavis.
Dolly has always been the dominant one.
But earlier today, they were both standing on a home made ramp, when I gave them some porridge. Dolly pecked at Mavis so that she could have the last bit. Mavis unfortunately toppled off the ramp. She ran back round to where Dolly was standing and attacked her again and again and has pretty much been going for her ever since. They're keeping a distance from each other (we have a large garden) at the moment but Dolly doesn't seem happy about it at all and ever time Mavis goes near her she goes for her.
I've never seen Mavis retaliate before and don't really know what to do. They've been together for about 3 years and never fought.

Is this common behaviour?

[loretta cluck]

Unusual that you havent had a reply from one of the experts, which unfortunately I arent.  I am hoping that things have settled down since yesterday, seeing as these 2 girls have been together for 3 years, and wouldnt normally fight with each other.  I have 5 girls, 2 of whom sometimes fight, but nothing major...it's generally an argument over a digging patch that has proved to have a couple of unearthed worms they squabble about, but doesnt continue.
Normally I'd guess you'd seperate them, but seeing as you've only 2, that doesnt seem right.  Is it worth looking at getting a couple more hens if this behaviour continues.

[8doubles]

Are they pals again yet ?
If not what happens at night , do they roost as far away from each other as possible ?

[ANHBUC]

It sounds like the last spat was the straw that broke the camels back.  Since Mavis has retaliated and taken the upper hand she will want to keep her position as top hen.  As long as there is no blood drawn they should be fine.  Hopefully things will settle down and Dolly will accept that she is no longer top hen.

[Sassy]

You may already do this and it doesn't work every time, but when you only have 2 hens when giving treats try to give in 2 piles of whatever or even 3. This way they can concentrate on the treat rather than stopping the other hen from getting it.