I have six chicks (3 BR and 3 RIR). One of the reds keeps twitching her head like she is shaking her head 'no'. She is fine in every other way. She is eating well and is feathering out extremely well. In fact she is more feathered than any of the others. Anyway, this twitching is very noticeable and I was wondering what it might be. She does have her neck feathers coming in so I was wondering if there might be some kind of irritation from that. I don't know. Anyone else run into this?