I have 4 chicks, two are 6 weeks old and two are 4 weeks old and we just moved them to the coop 4 days ago.
Every night I had to put them into the coop at night, and set them on the roost, but the two smaller ones would jump down and sleep on the entrance to the nest box.
You could always tell in the morning where they spent the night with the piles of poop left behind, and the smaller poop being in the nesting boxes.
I did close up the nesting boxes, and added a lower roost bar for the two smaller chicks and that worked well last night.
So last night, time to put them away, and I started with our RIR, who is the most timid, and put her inside, I went to get the others, and they were already on the ramp, so left them alone, and the other three all went inside, which was nice.
I like the idea of a light inside, and I will try that tonight, to entice them inside.