reading time: 7 minutes
Are you excited about baby chickens, but nervous about how to integrate them into your existing flock? Elizabeth Mac He guides you through the dynamics of the birds to keep everyone safe.
Written by Elizabeth Mac – Bringing home new chicks can be a stressful time, but it’s especially nerve-wracking when you have an existing flock. Old girls are on their way, they know their place, and they have a routine. Toss in a fresh mix of chicks, and everything is a mess. Fights can break out, and blood is often spilled. While you can’t avoid some clicking and fighting when integrating baby chickens, understanding flock dynamics and taking it slow will help you avoid at least some chicken fights.
Introductions
I have a friend who throws all of his new baby chickens in with the older ones and lets them fight until the feathers settle, which can take weeks. While this is one way to incorporate new additions, it can also be bloody. I prefer to adapt slowly to new additions to avoid spilling as much blood as possible – and to relieve my own personal stress!
Assuming you don’t have a broody hen to mother — and protect — the young chicks, keep the new chicks in their brooding space for the first few weeks. As soon as the temperatures get warm enough to spend some time outside, I’ll take my chicks to meander next to the old girls’ enclosed run. It’s their first chance to meet the older hens, but through the safety of an enclosed fence. It’s also fun to watch them walk on the grass for the first time!

Older chickens will be naturally curious and may be a little threatened by these new girls. They may strut back and forth and yell loudly. This is their way of showing their dominance over young chicks. Give them the opportunity to spend some time around each other, but securely, which will allow the older chickens to see the new chicks and reduce the threat of newcomers.
Separate pens
At about 4 to 6 weeks of age, the chicks begin to have their own feathers and can maintain their own body temperature. Weather permitting, I’d put them outside in a “kindergarten”. This pen is just a run timer where they’ll spend the day, and it’s right next to the larger run. This slow acclimation process allows the new and established flock to get to know each other. Every morning, I put the chicks in the makeshift run outside and let them spend the day next to their future home.

At first, older hens may “defend” their territory by guarding against strange newcomers. But once they get used to seeing starters, hopefully daily for two weeks, they’ll get on with their business. I let the new chicks play outside in the makeshift pen for about two weeks, long enough to get the new flock and the older flock used to each other. The pen is temporary, so it is not predator-proof. In the evening, take them inside the garage to their pen.
Is that a lot of work? Yes. But after some failed attempts to merge, the extra work will be worth it.
Moving day
There is much debate about how old chicks should be before merging with an existing flock. Should you mate when the chicks are smaller so they don’t come across as too much of a threat, or wait until they are larger and on par with the older hens?
The new chicks must be large enough to defend themselves from the older chickens. Otherwise, they could be pecked to death by an overly aggressive hen. I merged too early, and I regretted it. Now, I wait until the new girls are the same size as the older hens. By then, they will have had some time in their temporary run, and the herd that has been established will be used to their existence.
Once they’re old enough, I put the new girls in a race with the herd for some daytime bonding. This is a escort event, when I hang around to make sure there is no dogfight. Before I put them in the coop together unsupervised, I make sure the younger hens have shelter and hiding places to get away from the missing hen if needed. I’ve also put in extra water stations and feeding stations so there are fewer fights over mealtime.
pecking order
New chicks will quickly learn about the established selection order. Older hens will consider this. You will meet the attempt to cut off the food or water line with a quick tap. Assuming no rooster is in charge, the flock will always have a dominant hen. Chickens instinctively live in a hierarchical society. All members of an established flock know where they are—when to eat, where to dust bath, when it is their turn to go to roost, where to roost—and every element of flock dynamics is generated by this pecking order.

When new chicks are introduced into an established flock, the hierarchical arrangement is thrown into disarray. Chickens do not like change, and are sensitive to stress. Older hens may stop laying from the stress of the newcomers. When they are stressed, they can also become aggressive by pecking, pulling their feathers, fluffing their own feathers, and even patting other chickens. Once bloody aggressive, it can quickly become deadly, as the flock will be attracted to the sight of blood, and infected chickens can peck to death. When merging, it is a good idea to keep a wound kit on hand with an astringent powder to stop the bleeding.
While all this seems barbaric to humans, it is a herd’s way of creating a social order, a “government” that has functioned since the beginning of chicken time. The lowest chickens in the pecking order depend on the security of this dynamic. The dominant hen is the protector of the flock, and the lower-ranking hen warns of predator threats. The senior hen also explores a treat, such as earthworms or maggots. My dominant chicken screamed and flapped her wings so wildly one morning that I knew something was wrong. I ran to find a coyote wrapping the pen.
night integration
In a perfect world, once the new girls have mixed with the older hens, they should follow the older hens into the coop at night. But not always. When this happens, you can simply place the young chicks on the roost for the night. This is actually a good way to avoid a fight, and it’s one I’ve used to slowly merge the flocks.
By waiting until the older hens are roosting, relaxed, and sleepy, you reduce the risk of a bloody fight. Sit the new hens on the roost with the other hens. In the morning they will all get up and leave the barn to feed and be fed, paying little attention to who is sitting next to them. Make sure you have plenty of roosting areas; Each chicken needs about 10 inches, and larger birds need more space. Jamming them too tightly will cause unnecessary clicks and hassle.
Management tips
Isolate all new arrivals
Isolate all new chicks before introducing them to the flock. During this time, they will live in the nursery, where you can be monitored for any health issues. Even chicks that have been vaccinated should be quarantined until they are at least 4 weeks old.
feed
Growing hens will have different nutritional needs than older laying hens, so feeding time can be challenging. Layers need calcium for strong shells, and chicks need protein for strong bones. The best approach is to offer farm feed to everyone, and to supplement the diet of older chickens with shellfish shells. Farmer’s feed does not contain a lot of calcium, so it will not cause problems for young chicks. The added calcium in the oyster shell helps laying hens supplement their diet of tough eggshells. This is a good compromise for a mixed-age flock.
Safety in numbers
If you want to add to your flock, always try to get the same number or more new chicks than you already have. Adding one or two new chicks to a large flock is a recipe for disaster. The older flock will be dominant anyway, and the newer chick will not be able to defend itself against a gang.
Similar
If you have a flock of Rhode Island Reds and want to add a small, fluffy silky bantam, you’re asking for trouble. An established flock may not recognize silks as chickens and attack. If you want a variety of breeds, it’s a lot easier when everyone starts out as chicks. They grow up together and get to know each other. Attempting to integrate a silky-feathery Bantam into an existing flock of a different breed can lead to disastrous results.
Understanding flock dynamics will help you avoid a lot of the inevitable encounters between old and new hens, but not all. While you can never eliminate fights which are a normal part of the integration process, taking it slow and giving all the hens time to adjust will help reduce stress for everyone.
Freelance writer Elizabeth Mac He keeps a small flock of chickens on a 2-acre hobby farm outside of Omaha, Nebraska. Her work has appeared in Capper’s Farmer, Out Here, First for Women, Nebraskaland, and many other print and online publications. Her first book, Healing Springs & Other Stories, includes her introduction—and subsequent love affair—with raising chickens. Visit their website, Chickens in the Garden.