Last year I got 6 chickens (not sure what breed they are, they're mixed). two of them were roosters. over time we got a few legbars and then about 7 sex links. we keep the roosters by themselves and the legbars by themselves. currently we keep the older hens and the sex links in the same pen. they were doing pretty well for the first two, three months they were together. but recently, I have an older hen and a sex link that attack the other hens. if there's a hen laying or nesting, they jump up and push then down as a rooster would, and it almost looks like they're trying to rip the others' combs off. a lot of times I walk in the pen and see a few hens' combs all bloody. they've also been super defensive and tense around people, and they're usually not like that. I feel like this is not normal. any advice, help, or info? thanks!