I have two different ages of chicks, but they're only a week apart. I was keeping them in different brooders and earlier this week they all went into a corral in the coop. I tried putting a few together who hadn't been together before and the bigger ones were pecking at the eyes of the littler ones and being really mean. So, I partitioned off the corral into two sections with chicken wire so they could see each other and not fight. This was someone's idea on here and I wanted to say, altho I forgot who posted it, I really appreciate the info. It worked great!! With fingers crossed and holding my breath....I took the partition out today and they are getting along really well. There were a few moments of selecting their pecking order, but nothing brutal and nothing too harsh. The little ones stood their ground much better than I thought they would. This forum is just a big library of info on chickens and I really am happy I found it!!!