Plucking, Bullying, Illness?

[Dooze]

I am not at home right now, so I can't help my mother, but I was wondering if any of you can..
Yesterday she noticed two of our hens, almost 6 y/o Australorp, Inky, and Speckled Sussex, Huevo, had bare bums. We didn't think much of it since the Australorp would do that to herself in the past either to cool off or prevent poo from sticking. Today, the Australorp's bum is bloody. Sussex is fine. Inky panting (it's not that hot out), doesn't want to go outside, and is not afraid of people like she usually is. There isn't any bloody poop around the cage. Our 1 y/o polish Einstein's 'fro is bloody so we are afraid she's bullying them or making the bleeding worse.
If we were to remove someone from the coop, do we remove the bloody australorp or the supposed culprit? Any advice I can give to my mother?

 

[Dooze]

here is a picture my mother sent me

 

[azygous]

Without observing the flock dynamics to determine who may be bullying whom, it's impossible to recommend what to do, if anything.

Bare butts can be caused by a number of things, only one of which could be bullying. Worms, parasites, yeast infections are some other causes of bare, sore butts.

Those things can also make a hen feel unwell. Your mother needs to spend some time watching these chickens. This should tell her if the black one is being bullied or is indeed sick.

 

[aart]

The bloody butt needs to be closely examined and isolated for observation IMO.
Panting can be a sign of stress and/or pain....such difference behavior also indicates something is not right there.
Hope you can get home soon to help out.