I have an almost 6 week old RIR that seems to have a bit of a tic/twitch problem with her head. I first noticed it a couple weeks ago, but she could have possibly had it before that and I attributed it to itchy feathers, etc. She has always been off in her own little world doing her own thing- she seems a bit "slow" in some ways. But she's very active and seems to be healthy. Is this something that is really wrong (disease), or could something have happened to her as a just-hatched chick to cause this?