We have two ~18 week old hens that we are trying to integrate into our existing flock of 4 chickens. The 18 week old RIR ended up getting picked on, but we tried not to interfere with the pecking order. I went out last night and noticed that there was a gash that was about 1 inch by a 1/4 inch on the back of her neck. It was put there by our Silver Laced Wyandotte, which is 2 years old and was on the bottom of the pecking order in the group of 4, and seems to have it out for our little RIR. We rinsed the cut with saline solution, iodine and put some antibiotic ointment in there. The wyandotte has been put into the chicken tractor that we were using for the 2 smaller ones. The rest of the chickens now seem to get along for the most part. One of the older ones occasionally goes in for a peck on the RIR, but it is much calmer. I wish that the RIR would actually run away instead of squatting and shaking in terror when they come after her. Anyways I'm not sure how long to keep the wyandotte separated and what do we do if we put her back in with everyone and she tried to kill our RIR again. Any thoughts or suggestions would be greatly appreciated. Ideally we would prefer not to have to re-home anyone since they are our backyard pets and my wife would be devastated since we already had to re-home one of the new chickens this year when she turned out to be a he. Agent K as he is affectionally called now live at her parents a few hundred miles away. Thanks in advance for any help.