I have had 2 EE hens and one EE rooster for about 1 year. They are very friendly and docile. Well, yesterday I bought 3 ISA hens that are 14 months old and they are beating the crap out of my EE hens.
If you only bought them yesterday and without letting them get to know one another you just put them in together, then there's your problem right there.
It's a problem most of us have accidentally made at some point in the past, though, lol!
Just as with any other species you do not randomly put strangers in with one another without expecting fights and possibly deaths, and either way a heck of a lot of stress. There are rare exceptions to this rule but almost universally, they are flukes, freak occurrences not due to some magical integration trick.
They need at least a week to get to know each other (with mesh between them so they can't hurt one another), and that's not taking into consideration biosecurity. Quarantine periods are about a month on average but it's up to you if you use them. Bit late now though so damage control is the best bet now, give them immune boosters via diet etc to minimize disease spread.
They steer clear of the rooster and I thought he would keep them in line, but it seems he is letting them fight it out.
He's not stupid, then. It's not his job to 'keep them in line' --- roosters and hens have separate hierarchies, and his job is to keep other males in line, and the dominant hen's job is to keep other hens in line.
You never see an instinctive, mentally balanced adult male or female challenge the opposite sex for their social position. You naturally have a dominant male and a dominant female and they control their gender and not the other. It's not natural for a rooster to challenge a hen for the alpha hen position, lol.
My experiences with both my flock and others' flocks, where the roosters are allowed to interfere with hen-fights, showed it only ever makes things worse. The same is true for other species. Violence escalates down the track because when a male or any other third wheel interferes, he's preventing the females' fights from coming to their natural conclusion, and no matter what species you do this with, the more you interfere the more likely they are to resort to solving the problem permanently --- i.e. by killing their opponent instead of simply settling the pecking order. The problem is not solved when the male attacks one or both competitors, it's postponed and the actual problem builds, not dissipates. I've seen humans act as third wheels in cat and dog hierarchies and this lead to the permanent rejection of the very animal they were trying to make things better for.
I've only had one male attempt to interfere in hen fights, he wasn't a great male in any way which seems to generally be the case with instinct-lacking animals, and he only made things far worse than they had been before. It got stupid, to put it nicely, with that silly male making every single low-level and normal pecking-order squabble a fully blown three-wheel frenzy. For my hens' safety he had to go. He only interfered because he had only been raised with females and didn't know he wasn't one.
The risk to your hens is great when a normal fight between them is interrupted by an attack from the sides that was not announced, no challenge issued --- which is just abnormal behavior in the first place --- so if you want injured or dead hens, keep a male who attacks females. It's not healthy and not natural for the species. Males contest their hierarchy with males, females contest their hierarchy with females.
I have a dog house I put out there and that is where my EE's lay their eggs, but the ISA's wont let them in there now... Confused and not sure what to do to get them to where they get along.
Separate them, and start again, would probably be your best bet. Even if you don't have separate cages, you will most likely have to make some or get some, because it is always only a matter of time before anyone with more than two chickens needs another separate cage, for brooding or convalescents or breeding or whatever. There is always some emergency sooner or later.
If possible, (in fact I would take steps to make it possible even if it's currently not), I would separate all the Isabrowns from one another.
I would keep them where they can see one another as well as the EEs every single day so they get used to one another, but specifically get used to the EEs.
This will break up their gang mentality and give them time to view your EEs as a potential flock to join.
Being Isabrowns, it's not unlikely that they were completely isolated for generations from chickens of any other type or color and therefore have no tolerance for different looking birds, nor understanding of healthy social traits or behaviors. They are like inmates fresh from prison who need to learn to get along. That's an odd analogy but applies to the Isabrowns you can get around here, I don't know what it's like where you are though.
As they are separated, over the days they will lose their internal hierarchy and when you release the Isabrowns they will battle one another to resettle their hierarchy.
Best to release them after at least a week, one at a time, on different days probably, so the EEs can settle their hierarchy one-on-one with each Isabrown as she comes out, and have a few days to let it sink in. Perhaps leave two days on average between letting each Isa out so they can truly settle into their new roles.
Let the nastiest one out last, I reckon, so she will be down the very bottom of the pecking order, and she will be battling the other Isabrowns for dominance as well as the EEs, and is therefore much more likely to be tired and more willing to make peace as quickly as possible.
This is just a suggestion, though, it has worked for others but I can't guarantee it will work for you, but if nothing you do works it may be worth considering some birds are just extremely violent and better culled, whether you do that by rehoming or killing.
My Isabrowns weren't terrible socially, but physically I found them to be so inferior I won't bother with them ever again. They were alright characters and I went the extra mile to make their lives and health the best they could be, but their genetics were geared to work against them and due to this, their lives lacked a certain level of quality I believe is necessary for total health and humane/ethical husbandry.
Best wishes with your flock.
I did go out last evening and set up a separate area for laying so now there are three. When I went out this morning they were all gathering around me together without scratching or pecking at each other. and last night they were all side by side on the perching rod. I am building a new coop this summer because our existing coop was built out of scraps and I want better for my chickens, plus I want it to be pretty lol I didn't think I would get get into having chickens as much as I have, but I look at them the same way I do my dogs now. They are part of the big family!
