As you can tell, different ones of us have different experiences and different ways to do things. To me it’s not a case of you having to do it one certain way or civilization as we know it will be forever changed, it’s more of a case of how you choose to do it. There are risks, advantages, and disadvantages to all of them. Any of them can be successful, any of them can fail. Dealing with living animals is like that.
Some people let broody hens hatch together and are quite successful, either in the same nest or in separate nests with or without the same hatch days. Often the broody hens that hatch together work really well together to hatch and raise the chicks. To me, the advantage of this method is that they look cute and maybe it is more convenient for you.
But occasionally it does not work out. Sometimes the hens fight over the eggs or chicks. Eggs or chicks might get hurt. I had two broody hens on separate nests with hatch days over two weeks apart. When the first broody’s eggs started internal pipping and the chicks started chirping inside the eggs, the second broody abandoned her nest and fought the first broody over the eggs that were pipping. Half the eggs were destroyed. I’m not a fan of letting two broody hens hatch together. You can try it. It might work out great but then again, it might not. You don’t get guarantees with living animals.
Hens have been hatching and raising chicks with the flock since there were chickens. There are some risks with this but they are not extinct. It normally works out. If you go this route, mark the eggs you want her to hatch (I use a black Sharpie but others use something different) and start all the eggs at the same time. Then every day after the others have laid eggs, check under the broody and remove any eggs that don’t belong. As long as you remove them every day, they are still good to eat. Other hens might or might not lay eggs in her nest. If you leave the new eggs in there they will not hatch because incubation started later plus, if they build up to numbers the hen cannot cover them, you probably won’t get a lot of the old eggs to hatch. They will cool off and die if she cannot cover them all.
If you decide to isolate a broody hen from the flock fix up a cage where she cannot leave and other hens cannot get to her nest. Put in a nest (I find a dark nest works better than one in bright light), feed and water, and just a little extra room. A broody hen knows to not poop in her nest and mess up her eggs but she doesn’t know to not poop in feed or water. You’ll probably be changing the feed and water on a regular basis so give yourself reasonable access. I do not isolate my broody hens but I have moved them from one nest to another. It’s normally best to move her at night.
I generally leave my broody hens alone when they hatch. Mama knows a lot more about that than me, even if it is her first hatch. She seems to know instinctively when the hatch is over and it is time to bring the chicks off the nest. I’ve had hens bring the chicks off within 24 hours of the first one hatching, I’ve had hens wait about four days to bring them off. Each hatch is unique. The hen talks to the unhatched chicks after they internal pip so she can tell when the hatch is over. Chickens have been doing this by instinct since chickens were chickens. They are just better doing this than I am.
I leave my broody hens with the flock to raise their chicks. All I do is provide food and water where the chicks can get to them. I put rocks in the water bowls so the chicks can walk on the rocks instead of fall in the bowls and drown. And I clean out the old nest, throwing away all the trash and old bedding. The broody hen normally keeps the chicks in the coop a day or two before she takes them outside. Once she starts taking them outside, they pretty much spend all day every day outside. At night she normally takes them to a corner of the coop where they sleep on the floor.
My dominant roosters are never a threat to the chicks. They see these as their babies as long as they see them when they are still fairly young and before they are old enough to be seen as rivals. Sometimes the dominant rooster helps Mama take care of their babies, sometimes not, but mine have never threatened them.
Most of my hens aren’t much of a threat either. If a chick invades the older hen’s private space that hen is likely to peck it to teach it that it is bad chicken etiquette to bother your betters. It’s not an “I’m going to kill you” peck but more of a “Go away kid, you bother me”. It’s still enough to send the chick running back to the broody, who usually ignores this. But if that hen follows the chick to reinforce the lesson, Mama politely whips butt. No one threatens her babies.
Occasionally you get a hen that is a brute and will try to harm the chicks. Some broodies are more protective than others. I’ve never had a broody hen that would not protect her babies. I’ve never lost a chick to another adult flock member when a broody hen can protect her babies, but others have. They are living animals, they don’t come with guarantees. Immature cockerels are probably more dangerous than mature hens but Mama has no trouble taking care of immature cockerels. Most seem to enjoy it.
One key to this which Centrarchid sort of alluded to, in all this Mama needs some room to work with. If you have them shoehorned into a small space your risks go up. But if Mama doesn’t have enough room to work with, you are highly likely to have challenges when you integrate them yourself. Like everything else to do with chickens, more space is better than less space.
I like for the broody hen to raise the chicks with the flock. In my opinion the chicks learn better how to be chickens and Mama handles integration. She does not handle the pecking order issues. They will have to handle those themselves. After Mama weans them and until they are old enough to force their way into the flock hierarchy, they will almost certainly form a sub-flock and avoid the adult chickens as much as they can. Once the pullets start laying eggs they are normally mature enough to make their way into the pecking order. The cockerels are a whole other story. I’m not even going to try to cover them here. I have had hens wean their chicks at three weeks in the heat of summer and leave them alone to make their way with the flock. They did great.
For their own reasons, some people like to isolate the hen and chicks from the flock, either for the short term or until they have to reintegrate the broody and maybe later the chicks themselves. Some people take chicks away from the broody and raise them themselves. I’ll give you one warning but this posts too long already. If others want to talk about that, they can.
If you isolate a hen and her chicks, make sure the chicks cannot escape the protection of the broody hen. The other flock members can be a danger to the chicks if Mama is not there to protect them.
To sum up, there is no right way or wrong way to do any of this. We all do it differently for our own reasons. And the more room you can give them the better, but that is true with practically anything to do with chickens.