I have recently combined my two (now all female) flocks that are about 4 weeks age difference (March and April hatches this year). There are 22 EE in one flock, and 5 Production red, 2 light brahmas, and 5 bantum pullets in the other. There is a 4x8 hallway between the two flocks that I have recently opened within our 12 x 24 coop. Now they all intermingle, lay eggs in the others' nest box, hang out in each run. At night they definately roost back in their "home" coop but I keep the door open now constantly. So, last night, I made some effort to take construction materials out of coop, get floor cleaned up, etc. I had my husband come look at it. I said, watch this. I got a cup of scratch out, birds were milling about in each side of the coop, I then did my "Here Chick, chick, chick, chick, chick" several times. A thundering herd of 34 chickens came running to the hallway where I then poured the 1 cup (really one cup) of scratch in a line down the hall. My husband was almost ROFL when I looked up smiling among 34 chickens at my feet. You should have heard their thundering hoof sounds (it really did make a racket). He thought it hysterical that I had trained these guys to come running for a piddly amount of treat. I call it genius!