The main reason I even closed 2 out of the 3 windows was bcs this is the girls’ first night in the coop from the brooder and they were NOT happy when it started getting dark. So I closed them to darken the inside of the coop some. They eventually settled down.
NOW, I just have to get them to used the actual roost and not bed down in the pine shavings on the floor!
I'm heartless, so when the chicks got moved to the coop, I put them in (a cage for 2 days, as I have hens), shut the door, walked away and let them scream until it was dark and they finally gave up. They got over it.
Roosting will probably take some time. Some groups of chicks figure it out sooner, some much later. As I have adult birds mine roost "sooner" because they can copy the hens. Without adult birds, if you want them to roost, pick them up and put them on the roost once it's dark, to show them that's where to go, but don't be surprised if it takes a few weeks before it sinks in.