Black is a Calder Ranger. We've had her for about a year now and I think she's about 4 years old. She's always had a slightly redder abdomen than the others but it didn't seem to irritate her or be any problem. Recently it's been slightly swollen and redder than usual, looks painful but doesn't seem to hurt her. May be uncomfortable - when I pick her up and put she wiggles her legs around, didn't do that before. She also has stumps of feathers there, around the top of her legs and on her wings, but she's had them since we got her. She never used to peck the other chickens much, but now she actually chases them whenever they come near her and grab their feathers. Yesterday she pulled one out of one of the bantams. When I took them into their cage for the night and left them for a while, I came back to find she'd cornered Parsley who was crouching down on the floor while she pecked her (hard) on the back. She's been doing that to the other bantams too, and doesn't stop until I shout at her. None of the other chickens have ever acted like this before. When any of us go out into the garden, she'll run over and peck our clothes too. She pecks anything that'll let her peck it (even a bag of bedding left outside the shed!) But she never pecks herself or picks her own feathers out. Does any of this indicate anything? Thanks for your time!