Can anyone tell me why this is happening? I have a young Polish cross hen (just under a year old) that is suddenly showing major signs of anxiety. When I open up the coop in the morning, all of the other birds come running out into the yard, while this one bird begins to scream uncontrollably and flying into the walls of the coop until she knocks herself out or just faints. She comes to in about 20 seconds and then runs out of the coop. Yesterday,she slammed into the walls so hard that her head was bleeding. Has anyone ever heard of this and is there a cure?