Introducing New Chickens to an Established Flock

While there is no magic way to do it "right" (there is always the chance that one or more new chickens will be targeted and killed or pecked to bleeding) I can tell you what I have done for years and years with a good rate of success (never lost a single bird) and little things I have employed to prevent that from happening. Please keep in mind other people have used other techniques that have worked well for them too.

How Old?

These chicks are not old enough.

I start out by waiting till the chicks (I am referring to dual purpose laying hens mostly, meat breed grow faster) are 3 to 4 months old (sometimes older) until they have all grown up feathers and have STOPPED making baby chick noises (this gives them a little more size advantage and for some reason the old hens aren't as aggressive if they aren't making chick noises).

Momma Hen with Chicks

If my momma chicken has hatched out a clutch of chicks, I will leave the chicks in with her (in a separate area from the main flock) then when they are about half the size of her with all grown up feathers, and have basically stopped making baby chicks noises. Then I will introduce them to the main flock all together at once usually after dark. Momma chicken remembers the flock and her place in it so there is usually no problems there PLUS she will protect the chicks fiercely - this has worked EXCEEDINGLY well for me while introducing a hen with chicks back to the flock.

You will notice that as time goes by mamma chicken will spend less and less time with her chicks until she no longer treats them any different from any other member of the flock - no further action on your part is required to "wean" the chicks from the mom. Nature will take care of that for you and before you know it momma chicken will be laying eggs again.

Store Bought Chicks or New Adult Chickens

I don't let them "warm up" to each other by building adjoining pens where they can see each other or anything like that. It just adds alot more work to the introduction and in the end didn't ease the aggression of the established flock. There is nothing wrong with that approach, I just have never noticed that it helped that much. Chickens are birds not people, and therefore will not act like people.

When I introduce chicks to the main flock I do it at night in pitch dark - I don't even use a flash light. Some people say that the chickens wake up in the daylight and realize they have new flock members but the shock of introduction is reduced because the chickens don't recall when exactly the new birds came to be there. By default the new chickens just became part of the flock, they now just have to get their "flock hierarchy" figured out - where as if the new birds were introduced in the daylight the existing flock will more actively try to repel the invaders (and that's how they are usually seen - as a threat).
                           
I don't close them up in the coop together for several months (meaning, I will leave the coop door open to the run day and night) I find when I close them up - the older hens will just use the enclosed space as an excuse to beat the crap out of the new girls. Sometimes the new chicks will choose to perch outside at night for a long time - but eventually they will follow the rest into the coop for the night. Once or twice I have had to catch newbies, and toss their little butts into the coop (but I usually only have to do it once or twice before it dawns on them that it is just easier to go in the coop with the rest of the grown-up chickens than be caught and tossed inside).


CHICKEN TIP: Long handled fishing nets (which are commonly on sale in the spring) are really handy for quickly and safely catching flighty chickens who need to be relocated or examined in person. 

These chicks are getting closer to being old enough to combine, I still would give them more
time if they are still making chick noises.

                               
Our run is quite large and has multiple outdoor perches - so there is PLENTY of room for the new chicks to get away from the older hens, I have found this to be VERY helpful in preventing chick deaths. I also make sure there are 2 or 3 waterers and feeders spaced out around the run - this prevents one hen from guarding the only source of food or water.
                 
I also add them in all at once - they find safety in numbers and it tires out my old hens to chase around 4 or 5 new young hens. Then once introduced, I will check on them frequently and if any chicks are getting pecked to bleeding I will hit them with a little Wonder Dust - this is nice because the Wonder Dust clots the blood, stops the bleeding and makes the blood look like mud. Red blood will invite even more pecking from other flock members who otherwise would not have participated in the pecking.

BUT do know that there will be some butt kicking that goes on as they figure out their place in the flock - as humans we want to intervene and make them all get along, but I have found that they will find peace faster if I let them work things out (separating and then recombining sometimes helps, more often, is doesn't) even if it seems rather unfair and harsh. They will squawk, scream, chase each other, older hens will grab newer ones by the sensitive feathers on the back of the head. Just keep an eye out for blood, and within a couple of weeks they will usually figure things out. For months later there will be the occasional snipe from behind by an older hen - just reminding them that they are on the bottom of the pecking order, but it should grow to be a rare and maybe even humorous occasion.

Other Things You Can Do to Reduce Tension

Other things I will do to help is give them a flock block or two to peck on - maybe a couple of heads of cabbage, some oatmeal, just little things here and there to keep their interest off of the new chicks and on other things. Its been proven that installing nipple waterers also helps to reduce pecking as well.

My group free ranging - yes I left the water going in the stock tank too long and created a pond. Please note the alert Rooster, and how they stay grouped together for safety.

Timing

I actually like doing this in mid summer because my chickens are usually confined to the coop and run during that time since my gardens are in high gear producing. By the end of summer when the chickens get to free-range again, they have figured life out and are all one cohesive flock. I prefer it that way when they are outside of the protection of the run ranging. I don't like having a separate little group of newbies that are hanging out by themselves without the rooster, laying eggs in mysterious spots, trying to roost in trees for the night or that can't figure out how to get back into the coop....

But like I said this works for me and my situation, it may not work for your situation - hopefully there is something in this post that you will find helpful. If not - there are many other articles on internet covering the subject. Just remember that the worst can still happen, you can do everything right and still lose a chick during introductions. Take it as a learning experience and part of owning chickens, all we can do is our best.