Chick head twitches?

[Cierrascoop]

I'm not sure if this is an emergency or just me being overly paranoid. I got these babies a week ago and I've noticed the lot of them doing this strange super fast head shaking/twitching. I took my daughter's, Bug, out seperately to take a video of the movement I'm referring to. It's randomly through out the video. Could it be due to the finer wood shavings in their bedding causing irritation or something else? They seem okay aside from this. Eating, drinking, pooping. Here is a link to Bug making the motions. I think I did it right.

 

[SmiYa0126]

Looks healthy to me! My dogs ears perked up when they heard the chick peeping

 

[Razzlefrazzle]

It's been a while since I raised chicks, but something does seem to be bothering her. Ears, eyes, and nares clear? No strong odors either from the pine shavings or air fresheners or anything?