Silly chickens! I have 6 8 week olds ( 2 SS, 2 Delaware, 1 EE and 1 BR) and 6 4-5 week olds (2 Welsummers, 1 Cuckoo Marans, I EE, 1 Buff Brahma and 1 Golden sex link). I've had the older chicks in a big cardboard box brooder ( about 3'x4') and the younger chicks in a smaller cardboard brooder (about 2'x3') with a window covered w/ hardware cloth between the two so they could all get used to each other. As advised on this forum I waited till the youngest chick was 4 weeks old to group them together. Today is the day. So I added yet another box (4'x2.5') to this (hubby will be "just thrilled" when he sees how much of the garage is now taken up with all this but will maybe get the coop finished up more quickly-LOL) so I have 3 boxes strung in a row with doorways (about 1-2' wide or so) cut through and all the chicks can get to all the boxes. Mixing them together this afternoon seemed to go pretty well w/ all the exploring of new spaces. A little pecking and chasing from the big ones but nothing more than I expected and I've been checking on them regularly. Just now when I went in they are all taking a siesta crammed into the smallest box- the big ones in one corner under the lower (thus warmer) heat lamp that had been the little girls' and the little girl group crammed into the opposite corner under no lamp and noone under the higher lamp that the big girls had been using. The garage isn't too chilly now but will be tonite. I'm assuming they will all work this out somehow? The heat lamps are in their original positions. Do you think I should move them both so they are in the bigger box w/more "warm space"? Or just let them figure it out? Thanks!