Chick seems lethargic and keeps opening a closing her mouth repeatedly

[em4885]

Since this afternoon, my Buff Orpington chick (less than a week old) has been opening and closing her mouth nonstop. She isn't making any noise when she does it. The other 3 chicks are acting completely fine. Any idea what it could be? She's also acting lethargic and will sometimes fall asleep standing up. When she is sleeping, she's still moving her neck up and down. I have video of it but it doesn't seem I can post it here.

 

[Wyorp Rock]

Hi

Welcome To BYC

The video will be helpful.

Is she eating/drinking?
What are you feeding?
Do you offer any chick grit free choice?

Feel her crop to see if it's emptying, try to keep her hydrated and offer her some poultry vitamins or electrolytes.

Let us know how she's doing.