Sometimes being raised together makes them all get along, but after 'puberty' I usually put all the girls in one pen and all the boys in another. I find that once the hormones kick in, the boys are gonna fight/ spar with one another. Sometimes one is dominant and the others submissive, and they get along. But I've had some that beat each other bloody.I find that if they grow up together and stay together they are okay. I separated mine for breeding this year and now they are not so okayThey try to fight through the fencing, so I'm sure when they get free it will be ugly. I'll have to supervise the reintroduction and make sure no one gets seriously hurt while they sort it out. As for silkies, I can't peak for all of them, but mine are really gentle and non dominant. They hang out by themselves and no other chickens bug them. I'm not sure the others know what to make of them. One of my silkie roos is really "special". Sometimes he tries to confront the dog and when he jumps at her, he just falls over backwards. Are mine weird, or are they all like that? Sorry to bring up silkies here, but it seems like a lot of D'uccle people have silkies too......
My silkies can be just as bad. Falling over backwards seems to be normal for silkie roos. I think their blance is weird from all that head fluff. And they definitely can also fight if the dominant roo decides he doesn't like the others. Like people, I think they have to be judged on a case-by-case basis.
Interesting note: I donated some mf eggs to a local school science class. The babes went home with some students. One young man ended up with 3 roosters from his chicks. He has no hens at all, no hens in his area to tempt the roos or cause 'urges'. Two of the roos get along fine, but the third beats the daylights out of the other 2 all the time, and had to be penned up all alone. All three were raised together, handled the same from the start by their doting owner.