I have three pairs of chickens: two hens of two years age, two EE pullets 10 weeks old, and two Lav Ameraucanas (sex unknown) of 6 and 7 weeks age. The hens are next to, but separated from all the youngsters. They have had very limited and supervised get togethers that consisted of very aggressive attacks of the EEs with me stepping in to prevent injury. The four youngsters are sharing an enclosure, but they have their own sleeping areas due to the coop I managed to find. In the picture below, the hen area is to the left beyond the white wire door. The long white coop is where the youngsters sleep: it has a wire bottom and is divided into four sections. Both ends are wire enclosed and I put in roost bars. Each end unit has a hole cut in the inner wall that accesses the section next to it. Those are fully enclosed and do not connect to one another. Right now they are each set up to hold water and food for the pairs of pullets. (I will be adding more ventilation soon). The 30x6 area is enclosed except where I ran out of netting (where the palm fronds are). I am trying not to interfere with how the two pairs of pullets interact. My hope has been to let the small birds work out a relationship before throwing the hens into the mix. So far the two pairs are refusing to integrate: They stick together in their pairs, and both the older ones (EE) will chase and peck the LA's. So far there has been no physical damage. [The larger EE has not plucked feathers from anyone, but does eat feathers she finds on the ground. I am a bit concerned this may evolve into feather picking...none of my existing hens ever ate feathers.] Honestly, I don't like how much the EE's are stressing the younger pair, so I lock away one set and then the other for a while each day, so the LA's get some respite. I want to start introducing the EE's to the hens more intensely, but I am worried that as the hens pick on them and put them in their places, that they--in turn--will act even more aggressive toward the LA's. What is your experience? Is aggression something that spreads like the flu? If I do let the hens and the EE's interact, should I then keep the EE's completely apart from the LA's until the LA's are ready to join the bigger birds? It seems they would probably then just end up getting picked on by all four bigger birds... Any advice would be greatly appreciated!