UPDATE!!! Oh how I wish I had pictures.
Today the chicks are 2 weeks old. This is day 3 of working on making a safer yard area for the chickens before we have the chicks come out of the MHP brooder, it will still be a couple days. Bill roughly mowed the grass in the yard so there are different levels to interest the birds. Then Bill put in a couple of perches into the brooder, and I changed the hay completely, plus reconfigured MHP to be higher. Heating pad setting has been on "1" for days-- it's been 72 lows overnight and they often sleep on top not inside. Because we were completely revamping the brooder, to keep them safe we took them out and put them in the finch cage I used as a landing base for the hatch. As a result, the adult chickens were able to get a good long look at the chicks for the first time and hear them because they were out in the open and the big coop door was open so it was light in there. The coop is a bit dark because it's a barn stall.
So, we had a big rainstorm late in the afternoon and I took the opportunity to improve the drainage around the barn-- that big overhang doesn't have gutters and the area wasn't contoured properly and when we get lots of rain it was running off toward the barn instead of away. Anyway point is, the chickens saw us working very hard on their space. And when I looked in on them before heading back into the house, for the very first time they are spread out over 2 different levels of the roosts in there. We have four roosts that are 2x4s laid flat, each one another step higher. The ten chickens have always perched on 1 single roost, the highest one. But there they were, all spread out on 2 roosts, lounging and looking happy and relaxed. And I realized, they are making room for the littles! They are making space for them, just like we've been making space for them.
I'm awed by how cool that is.