Orpington not roosting

[ioliff]

My hens are 7 months old and are perfectly healthy and wonderful. They go into thier hen house at night and roost, come down in the morning, lay their eggs etc. BUT, the past few nights my buff orphington isn't roosting at night. When we go to close the hen house door, all the other girls are up on the roost, and she's either standing (or tonight lying) on the floor of the hen house. The roost is not too high, I've seen her up on a much higher roost during the day both yesterday and today. My husband and I have picked her up and put her on the roost the last couple nights when we find her, and she stays there. Any ideas why she is not roosting? Should we keep putting her up there or just let her be?

 

[PheasantsFirst]

I've got a couple birds that don't roost often, I think some just don't or there may not be enough room. And