We have multiple pens because i just hate the pecking order issue. One pen has 3 Showgirls and 3 Silkies, who can get fussy with each other at times, but in general have gotten along for years. Well lately, one of the Showgirls has gotten really mean. Later in the day and close to bedtime, i have seen Cotton Ball jumping on top of the other chickens and just wailing on them. The other hens will squat in submission, but that doesn't stop her from brutalizing them. No blood yet, but it's very disturbing and i hate to see the others fleeing in terror when she comes near. i pulled her out the other evening to give the others a chance to peck in peace before bedtime. But i'm wondering why she has become like this lately after 4-5 years of getting along with her pen mates.