roosting for chicks

I've had four young chickens for the past two weeks. They're in a makeshift brooder in the house, and there are no older chickens. At this point, I have a 6-week-old, a 7-week-old, and two 10- through 12-week-olds. At night, they don't go up on their roost bar to sleep. They'll sleep in a puppy...

Alright, I've got two roost for my chicks in their pen that's on the grass and the only one roosting insists on the waterer and the feeder. I'm also wondering when the other ones are going to start roosting as well.

They are in a water trough ive tried everything any ideas to anchor one up where it will not keep falling down. .heres photo of what they are in to help