I have a week old EE chick who has been acting very odd lately. Up until yesterday she was the best chick in the group, friendly, energetic, and relaxed. But yesterday she started to shake her head side to side as if looking around. This lasts for a few seconds and then she runs in tight circles, very quickly. Once she laid her head all the back until it touched her back and just sat there. This happens in stints and then she acts perfectly normal. She's the biggest and otherwise healthiest in the bunch. Panicked and dizzy would be the best ways to describe it. Any ideas?