Chick question - open mouth shaking head

[WesterBee]

Hey BYCers!
Hoping for some advice on my 4 week old Bielefelder chick. Last night she was doing this open mouth head shaking action.

Her crop is empty this morning and she is eating and drinking. Any ideas advice as to what could be going on?

 

[FirstTimeChikens]

I'm extremely new to chickens, but I've seen some of mine do that and they seem to be normal. I remember freaking out when I saw them wiping their beaks or stretching their legs, but turns out that's normal too. In case it's not, I always check for pasty butt... but this is my first set of chickens, so I'm more curious as to what the experts have to say.

 

[swamphiker]

It looks like she is adjusting her crop to me. If so, it is normal!