I only have 4 chooks - 2 white and 2 red. # of them are less than a year old. The 4th (red one) could be any age. She stopped laying about 4 months ago, but was just as chirpy and happy as the others. Until about a week ago. She is now always on her own, usually holed up under the house. She comes out for feeding and goes to bed like all of the rest, but she stands around with her feathers puffed up and often just on one leg. When she lays down, she just falls flat on her side and she appears to be dead, with her legs just spread out. The only change I can notice is that her legs have a crusty sort of look on her shins area (it would be OUR shins - don't know what it is for chooks). The scaly stuff has a grey colour. But that's the only change. I worm them regularly. Please help.