I'm a new chicken parent and got my first flock of 6 chickens in May. And one chick stood out of my flock right from the start, the whole way home she peeped unless I held her in my lap where she would sleep. And as she grew she just wasn't like the others. She didn't do what the others would do. She ate and would drink without issue but when outside she wouldn't run around or forage, I thought she was sick at first. But after awhile and reading up on her I realized she has a vision problem, she isn't blind but has a problem with depth and so trips or falls over uneven surfaces. She also can't get on the perches on the roost since she will not jump up due to her vision. She would lay on the floor and cry for the others, so luckily my handle boyfriend came to the rescue. And make her a latter so she can climb up onto the perch with her friends. She is 16 weeks old and doing so well and doesn't let she disability stop her!!
