have an 11 mo BO pullet that I noticed yesterday is missing feathers on back of neck. no blood and can't see any pests. I DID introduce 5 4 mo pullets a couple of weeks ago and they've done well and noticed last night that 3 of new group were squeezed in with old group and the BO with missing feathers was mad. she pecked me quite aggressively and I moved the 3 new pullets to another area. I have a roost but everyone beds down in their nest area(which is large enuf for everyone so just moved babies to lower area) will try to make another HIGHER roost because THAT could be the problem(their current roost,that they don't like at night, is 18" off floor so maybe need it higher?) kindof thinking in print so forgive me.they have plenty of room at night but scrunch together. buffy is on far right with little red(NH red) and hawkish(ameracauna) next to her.