You didn't say how old they are, or I missed it. You could sprinkle a little scratch in coop before bed to coax them in. They will soon associate whatever cup or dish your bringing scratch in, and follow you in. My 5 week olds I've had to coax in a little earlier to their brooder coop to avoid the roost rumble that the bigs have at dusk. Their not fully integrated yet, the big girls are more welcoming, but my roo is not so much. It's taking a bit, having to over see him during integration.
Best of luck ..