Our chicks are 6 weeks old and up 'till now not one problem. Well they were cooped up for 5 days before I let them out in the run. They spent 6 hours out yesterday and at dusk 5 of them made it up the ramp and in the coop. I noticed Ester our Easter Egger pacing in the run, looking up and into the coop where all her sisters had gone. She made an attempt to fly up but missed and continued to pace in the run. I went out and she was chirping quite a bit so I intervened. I crawled into the run and picked her up and put her at the top of the ramp and gave her a shove in. She is not going up the ramp in the coop to the roost with the other birds at night. Is she retarded or afraid of heights?