I have 3 barred rocks and 3 Rhode Island reds. I got these when the barred rocks were a week old and the Rhodes were a month old. I got them about a month ago. When I got home from work yesterday I noticed one of the barred rocks was laying on her back. I picked her up and she seemed stiff in the legs. It appeared that her neck was weak like it was broke. I couldn't find any marks on her, so I separated her from the others and hoped she might have just been feeling bad. When I checked this morning, she was dead. There was not much difference in the size of the rocks and Rhodes until recently. Now the Rhodes are much bigger. I think, somehow, one of the Rhodes broke her neck. I have a perch in the brooder for them, but it's only two inches high. I see no way this could have hurt her. An attack by her own could be the only animal that could have got to her. Like I said, my diagnosis is its neck was broken and it had some paralysis. Does the idea of another chick breaking her neck sound extreme? And as I have been researching, I think they may be bored and I need to further research the activities I can provide them. What's your thoughts?