Bantams roosting in a tree, how do I train them to roost inside?

[Fudgefluffernutter]

I was given two young bantam Cochin pullets, who insist on roosting up in a sycamore sapling right outside the coop. All 10 other hens go in the coop to roost, there is no aggression towards the littles, and when I first got them, they came in the coop with the others at night. I even tried cutting one of the sycamore saplings and mounting it in the coop so they have a tree in there, but they still go into the tree about an hour before the other ladies roost. They like perching up and in the little branches, which I will try to replicate with a better coop tree… any ideas to get them trained? It’s been really warm here, too, so I don’t blame them for wanting to sleep in the cool night air, but I don’t want anything to get them, either! Current coop setup, there is another ladder to the left out of the photo.

 

[The Coop Crew]

Maybe put them in the coop before they have the chance to roost in the tree? After a couple nights hopefully they will be used to the coop again.

 

[BigBlueHen53]

Could you lock everyone in the coop for three or four days and nights to get them used to sleeping in there?