pullets wont roost - causing coccidia

[ghiagirl]

I have (4) 18 week old pullets that since I got them will not roost. At night, they all 4 gather in 1 nesting box to sleep. I've tried to set them on the roost after dark but they hop back down and get in nest box. I've had 2 bouts of coccidia and I'm sure its because they are sleeping in their own feces - even tho I clean out the box every morning.
How can I get them to roost?
Also, since I've had one separated from flock for 3 days (she is the smallest of the 4), will there be trouble intergrating her back into the flock once she is well? The other 3 seem fine but I will be treating them all with Corid later today (once I find some - my TS store is terrible with being out of stock on everything). I am currently using the medicated chick feed with Amiprolium in it.

 

[Ardj]

How high is the roost? When i put my hens in the coop for the first time i did put the plastic buckets in their nesting baskets so they couldn't sit in them until they learned to sit on the roost. And i made the roost like a ladder. They were sitting on the lowest one in the beginning. Then when they were bigger they moved on the higher one. When they learned to sleep on the roost i took the buckets out of nesting baskets. It worked out perfectly for me.

 

[ghiagirl]

The roost is 12" from floor. When I tried blocking the best boxes, they huddled in the floor. I'll try placing a lower roost.

 

[Ardj]

Yes try to put a lower roost and maybe put some treats for them on it? Maybe that will work.