Integrating as young chicks is much much easier than older birds, setting the space up to facilitate might not be so easy but well worth the trouble IMO. Tiny chicks (4-6 weeks old) are not as much of a 'threat' to the adult birds as older chicks (3-4 months old). Making the access 'doors' to the 'safe' chick space is much easier with the size differential of tiny chicks vs adults. Tiny chicks are fast so hard for the adults to 'catch'.

My setup is kinda complicated, but here are 2 other simpler methods that work just as well:
https://www.backyardchickens.com/articles/short-on-time-recycle-a-prefab-brooder.73985/
https://www.backyardchickens.com/articles/my-coop-brooder-and-integration.74591/


In 2016 I integrated the chicks at about 4 weeks old. Chicks went into the coop at 1 week with their heater, separated from the main flock by a wood and mesh temporary wall. I had added the doors and put the wall up before taking chicks out to the coop and found a couple of my slimmer hens could get through, glad I inadvertently 'tested' the door sizes. Found I had to narrow the tiny door openings to about 3 1/2" to exclude those skinny hens from getting through. They had their own feed, water, roost, and run in the 'coop partition' as I call it. Door installation for the lower part of the temporary partition wall. Smaller doors are about 4" high. Larger center door is 5x7" but I had to add a piece of wood (not shown here) to make that opening only 3 1/2" wide.



I use a heating pad for brooder heat, some call it the MHP (mama heating pad), I call it the Pseudo Brooder 'Plate'. Pad legs sit on a groove on an upside-down wire crate tray set on bricks to keep it above the shavings. Pull the tray out every few days to scrape poops off. I put feed and water on a tote lid for the first week or so, then they go on bricks.



And add some straw around the heater if ambient temps fall low.



During a 3 week interval, the chicks learned about ramps and explored the great outdoors. I lined the run with some chicken wire to keep them from escaping thru the 14ga 2x4 welded wire, not a good idea as it created some openings big enough to get a chick head thru but not get it back out. Lost one, think it got stuck and panicked breaking its neck.

Replaced the chicken wire with 1/2" hardware cloth 2 feet high. Also lined the main run with HC to accommodate the chicks containment as well as to hold in the deep litter I began to use later in the summer.

700






Getting chicks back into the coop at night is a common problem, chasing and catching them is a PITA so I rigged up the 'chick corral' with some 1x2x24 fencing, Attached at one end to the run wall, then a hinged 'door'. Open the door, 'chase' them around the wall and into the 'trap', close the door and pick them up. Worked pretty well, reduced everyones' stress level, and saved significant evening chore time.



At 4 weeks I opened the three tiny doors in the wood part of the wall and 'taught' them how to go in and out. I used a barrier at first to make sure they could get back thru the doors without having to chase them all over the main coop, might have anal overkill but it's what I did. I grabbed a couple of chicks and stuffed them thru the doors, then walked around and 'scared' them back thru the doors. Repeated this a few times and pretty soon they were all checking it out and going back forth with ease. I left this barrier up for a day or so.




The next step was to shut the main pop door to exclude all the adult birds out in the run and took the barrier down so the chicks could explore the main coop by themselves for an hour or so. Then I happened into the coop and only one of the hens was in the coop, one of the most docile (Henny), so I shut the main pop door keeping Henny in and tall the other bigs out and opened the chick doors. They came tumbling into the main coop and checked out Henny, she gave them a few pecks but mostly ignored them. So I opened the main pop door and watched the fun begin.




There were a few pecks, of course, some of the bigs pestered the little more than others, but overall it was much less dramatic than usual. I think the chicks were less of a 'threat' than when I used to wait until the chicks were larger...and a smaller, faster target to hit, haha! I put up a temporary roost in the main coop for them to get used to, a place to 'hide' and later use to sleep until the point of lay prompts them to integrate into the main pecking order.



At 6 weeks I took down the wall completely. They all got along pretty darn well, though chicks definitely remain the 'subflock' until the point of lay. It was nice to get the integration over sooner rather than later and because I had way more chicks this year it was a very good move to integrate younger,
it's pretty crowded out there, but they were already used to each other. There are roosts and other places to 'hide' or 'get away' from any aggression.









It definitely reduced the stress and fighting that happens when integrating new chicks at the commonly cited (by me as well) at least 8 weeks or when they are of the same size.

Here are a couple of other good setups for integrating chicks:
https://www.backyardchickens.com/articles/short-on-time-recycle-a-prefab-brooder.73985/
https://www.backyardchickens.com/articles/my-coop-brooder-and-integration.74591/


If you have any questions, please ask them in this thread:
https://www.backyardchickens.com/t/1159151/integrating-chicks-into-flock-at-4-weeks-old
as I don't get notifications for article comments.