Hmmm, that is a good question. They can and do fight, but usually they get things worked out. I have kept up to 11 roosters together in a rooster pen, and they all got along fine, but when I let them out they competed vigorously for new territory. So it depends somewhat on the circumstances. it also depends a little on the breed, and maybe on whether they were raised together. My white Silkie males squabble and fight endlessly, but they rarely draw blood or hurt each other. They have attacked people with serious intent. The black and blue Silkies don't fight with anybody. My Light Sussex occasionally squabble, but they adhere to and respect a well defined hierarchy. and it depends on the line they come from. And it depends on the mother, because disposition and behavior characteristics are inherited from the female. I think there must be a forum thread dedicated to this topic. Flocks with Roos are like the best of the Soaps: never a dull moment. And of course they are great eye candy.