I have 8 pullets, raised from day old's together, a mix of hatchery stock layer breeds that are 22 and 23 weeks old...(2golden SL, 2Amber SL, 3production RIR'S, and 1 BR). A few weeks ago when they began to lay eggs I started to notice some nasty pecking behavior( mostly towards one immature white pullet, chasing and an occasional peck or feather pull), a bit more than usual but still not too bad. Mostly it occurred in the mornings when they were confined to the coop(training to lay in nest boxes not yard) and at night(seemed like normal squabbles over prime roosting spots). Up until two weeks ago when the kids started back to school all was going ok, now the behavior has escalated. There are three hens in particular that are ruthless! the BR chases the little immature hen constantly. She guards the feeder, and only allows the other two RIR(dominate girls) to eat. Her chasing in the coop and run is relentless and it escalated to her seeking out and terrorizing the little pullet. The RIR's gang up too they stare into the other chicks eyes and they freeze and submit. The one RIR guards the nest boxes. If anyone goes into lay she stands over them and picks there combs and heads and sometimes is so mean they bail and run(no eggs). The two RIR's have become horrible on roost at dusk too. They peck the feet and heads of the hens next to them until they bail. They climb down off of prime spot just to unroost other girls and go back to prime spot etc etc....you get the picture....I've just noticed everyone stressed and afraid of these three, the coop is turned upside down from the chase game, and the little white pullet started to try hiding/sleeping in nest box face first or the others are afraid to go into coop or near feed to avoid confrontation. This is what I have done in hopes of helping the situation 1. turned off extra lighting(read it can cause stress and agitation) 2. added extra feeders and waterers so they all can find a spot(inside one each food and water, two each outside) 3.bought a small cheap coop on craigs list to isolate bad girls 4.increased feed to 20% from 16% protien 5.drilled holes in Gatorade bottles and filled with scratch for distraction while in coop and run. With all these attempts the change in behavior was minimal. I isolated the BR and one of the RIR's and she freaked and rubbed her beak bloody on the hardware cloth in the new pen(wouldn't lay eggs) trashed cage and was going to hurt herself trying to get to back to others. The RIR layed eggs didn't seem to mind, but started attacking the BR. When free ranging mind you, they all seem to get along ok,( i even kept them all penned together at night in the safer big coop and used the ISO pen only during the day) or are just able to get enough space to not have the escalated type confrontations like in the coop and run. Today I got desperate, (these chickens are stressing me out!) I called National Band Co last Wed and ordered pinless peepers. I was not wanting to resort to this, have never tried them, and saw them on other threads as a possible solution to bully hens. So DH and I decided to apply them to the three "bad girls" this morning so we could watch and make sure it was safe and it didn't make things worse. Well......it wasn't to hard to get them on..... the BR pullet shook her head a few time took a couple steps and for the most part was eating drinking and acting ok. The RIR's were very disoriented stepping sideways having trouble eating and drinking and pecking(i sprinkled crack on ground to keep them occupied so others wouldn't peck them and they would focus on crack not new weird eye blockers but couldn't figure out how to eat it).They're combs are alot bigger and are a bit folded under peepers no gaps(the BR has a small comb and can see a tiny bit forward or is just smarter and has more coordination) the other two were really disoriented. As the day progressed I noticed a calm in the flock, well the peeper chicks were struggling but everyone else was calmer. I was getting worried about the peeper girls and if they were getting food and water ok. They kept trying, figured out the water, but the feeder is still a challenge. They seem to be able to get to the feed in open pails(xtras I added) but kept trying their regular feeder. There was one fight between the BR and the other peeperd RIR head honcho late this afternoon. It was more escalated than usual(RIRjumped on her back with feet out first like rooster), but it only lasted a few seconds! the drama on the roost tonight was almost zip!! little picked on pullet is on the head honcho roost!! in between the mean two RIR peepers!! I let them out quite a bit today and am nervous about leaving them penned tomorrow, but with no one home, my fears of letting them free range alone, out weigh the fear of stress in the pen. We got four eggs today( only 5 layers so far for sure), one soft one, not sure who layed that one, a stressed hen or a new beginner pullet, at least they were all in the nest boxes. Hope tomorrow goes better, i am concerned about the peeper girls functioning. The other pullets can beat them to the treats and scratch cause they can't see(somehow the peepered BR gets some, she is fat and loves her food!). If any one has any more ideas or suggestions, I'd be open for any experience with these things. I am trying to avoid the ultimate isolation(oven) and wished I had purchased all golden and amber SL they are so docile and hardly pick each other at all. I never remember our RIR's years ago being this aggressive, and went on that in making the decision to have a few(never again). These three are good layers(almost daily), and are very beautiful chickens! makes it hard to cull them. I'm very stressed, don't want to cull my birds, just wanted a few mellow laying hens for eggs!! I guess "few" may be the key word if the peepers fail!! Wondering if I made the mistake of letting them out most of the summer, and now they have to be penned and can't handle the confinement. OT's bear with me, yes another inexperienced backyard wonder, with i'm sure an age old issue. I just hate to see the birds pick each other bloody and bald and have terror strike my other hens.