First let me say I have read and re-read these two threads: https://www.backyardchickens.com/a/adding-to-your-flock and https://www.backyardchickens.com/t/1098683/introducing-new-chickens-to-old-flock The 6 chicks share a small coop at night but are put out in a dog kennel (~50 sq. ft.) next to the main run with my other hens and the rooster during the day. This has been the case for at least a month. I was going to wait til about the 16 wk mark to integrate them as the one thread suggests and also to let their "voices" finish changing. But one of them in particular is starting to get a bit aggressive with the others pulling feathers and whatnot. Should I integrate them sooner so the rooster can establish order? It's just him and four hens left from my original flock.
12 weeks is a fine age, especially since they've already been seeing each other for a month. Make sure you put them together at night, and let them out early the next day. It's also a good idea to place a secondary feeder and waterer away from your main ones, so the young pullets will have access to feed and water away from the big bird's territory.
