hens getting along?

[annie3001]

just wondering how common it is for hens to fight or pick on another hen?
i own 5 hens, about 4 months old.
only when they are free ranging do i see hair stand up on some of them.
and i see them mostly go after one particular hen. i feel bad for her.
I notice in their run, they are all fine, but its when i let them out of the run to eat grass, bugs etc.
any idears?
also in their main coop they all sleep on the roost comfortably together.
i just hate breaking up arguments with them. i usually go in the middle and say "knock it off girls" and they stop.

 

[gritsar]

If no blood is being drawn, I let them sort it out.
Somebody has to be at the top of the pecking order and sadly that means somebody is also at the bottom. They learn to cope with their lot in life.