A Tort Twitch...Normal?

[HappyHermanns]

We have noticed since we got our babies (3 Hermann'sTortoises) that while they are active they are a bit twitchy.. not too crazy, but when they breath it's like their head almost bobs a bit or something..
I just assumed this was their nerves and was a normal thing for them. We have had our guys a few weeks now and they are still doing it, so I thought I should check..
Would hate to find out that we aren't doing something right for them..

They don't do it while resting or sleeping.
I took a short video but it wont let me upload it here..
Thanks in advance!

 

[WithLisa]

Totally normal breathing movement.
Their shell can't expand like a human rib cage, so the have to move something else.

 

[HappyHermanns]

Totally normal breathing movement.
Their shell can't expand like a human rib cage, so the have to move something else.

Ok, I thought it would be something like that.. whew. lol
It is a very cute twitch anyway.