We are in the process of building a bigger coop and run for our pullets. We have a hen that is about a year old that we think killed 2 of them so we want to split them up. They free range during the day and at night the pullets are still going to the coop we kept them in when they were babies. Its only supposed to hold 6 chickens and we currently have 12. I have a few hens that I would like to also add to the new coop with them. I want to separate the more aggressive "red Rangers" from all of them because they all pick on the pullets. I will probably not free range the aggressive ones for awhile until I feel they are all safe which is why I want to separate the other few hens from them as well. Any suggestions in doing this in the most stress free way would be appreciated.