New chickens not sleeping in the coop at night

[KStud]

I have a flock of 6 hens. Three of them I got in February, raise inside until juveniles, introduced them to the outside run and coop a few weeks ago. It was a rocky start, one of my hen is definitely boss. Everything has quieted down considerably in the run, but the younger chickens roost outside in the rafters an not in the coop. I have no idea how to get them to go into the coop at night with the three other hens. Any suggestions?

 

[Folly's place]

How much space in the coop? Is your run safe overnight? You can move them to the inside roosts at night until they get the idea to go there. Mary

 

[KStud]

Thanks Mary. Yes, the run is very secure. I was worried about locking them in at night due to the fact they are lowest on the peeking order and they still get pushed around during the day. No feathers flying, but chased a bit...

 

[aart]

But how big (feet by feet) is your coop/run?
Posting a pic would help.
Crowding can make for fighting.