Intergrade

[Steelewoman]

The 12 week olds are in the to coop that has the small coop

 

[Steelewoman]

Where are the younger ones housed in relation in that photo? The brown part on the right? Any closer photos showing what's inside, because I can see some feeders and maybe a pallet, but there's no other clutter: https://www.backyardchickens.com/threads/a-cluttered-run.1323792/

Have you tried ALL the birds together?

Yes the. Brown side