Hi. I am glad I found this thread. I found my daughter's 5-month old light brahma acting the same way about an hour ago. I noticed her earlier this morning sitting in one corner of the coop. After I went walking, I noticed her sitting in the same spot, and when another pullet jumped on top and around her, she acted like she couldn't move. I picked her up and noticed how light she felt. She acted normally yesterday, but she must not have been eating well for several days. I moved her to an isolation pen and gave her water and food, but I think she is going to die. I, too, don't know what is wrong with her. There were several other pullets in the pen with her, and they are all acting fine. I would like to know what this is even if she dies from it because I want to treat the other pullets if possible so they don't die. I, too felt her vent area--not swollen, but it does look like she may have had diarrhea, but it didn't look bloody. I also checked under her wings for mites--no mites. I did not check the crop--I don't really know how do do that. All she wants to do is lay in that same spot and sleep. When she breathes, she looks like she is shaking, like she is shivering. It is one of my daughter's 4H poultry chain pullets, so I would really love to "heal" her. My daughter is only 8 and loves her chickens. She'll be so devastated if one of them dies. I know that is just part of life, but it is so hard for an 8 year old. Any input and help would be much appreciated.