Why is my chick opening and closign his mouth?

[AikoGami]

Before he did this I was giving him some little scratches behind his neck, like how you do parrots, and then he stared doing this and I began to worry. After I stopped he only did It a few times for a minute or so. Is it maybe because of the way his feathers moved when i scratched him? Should I not pet/scratch chicks? He's 2 months old. Sorry I'm such a worry chick mama
Hope I inserted the video correctly, I'm new to this
Chick video opening mouth

 

[yakitori]

It looks like he's adjusting his crop, most likely nothing to worry about, especially if he's acting just fine otherwise

 

[AikoGami]

It looks like he's adjusting his crop, most likely nothing to worry about, especially if he's acting just fine otherwise

Yes, he went to acting normal afterwards. Do you think I shouldn't give him scratches anymore?

 

[yakitori]

If he’s uncomfortable, he’ll let you know. I used to have a chicken that would fall asleep in my lap with her necked stretched out and relaxed. I stroked her all the way from her head to her tail, she loved it

 

[AikoGami]

If he’s uncomfortable, he’ll let you know. I used to have a chicken that would fall asleep in my lap with her necked stretched out and relaxed. I stroked her all the way from her head to her tail, she loved it

Thank you for the help!