New flock training

[biblechicks]

My 12 week old flock of seven have a great hen house and good sized run and they are all very healthy. They go into the coop at night, but will not sleep on their new roost. They prefer to sleep all huddled together, as they have since they were tiny new chicks.
I have a nice step for them and have tried placing them on the roost (repeatedly) enticing them with treats, nothing is working.
Any suggestions?

 

[chickens really]

They are still young and will start roosting once a bit older. Still comfy cuddling on the floor. Mine are 6 weeks today and only a few roost, most still sleep on the floor.