I'm new to raising chickens so please forgive me for what might be some very basic questions. I have four hens that are a cross between a Rhode Island Red and White Rock. They are free ranged during the day and supplemented with layer's pellets. Last night they all looked normal and ran to the coop when I brought food. All of them ate normally. This morning when I opened it up to let them out for the day, one of the hens was laying on it's side, breathing somewhat heavy. I tried standing her up but she seems very weak. Her head is kind of twisted sideways and her legs are pulled up beneath her. All her feathers look normal and I don't readily see any mites or lice on her. However, a few weeks ago I saw what I thought were worms in the fecal matter of one of the hens (not sure which) on one occasion. I began treating all the hens with Rooster Booster about a week ago. Could this behavior be caused by worms? Is there something else that could be causing this problem? I feel so badly she's ill and that I lack the skills necessary to help her. Please advise if you can. Thank you!