"Twittering" sound?

[Canucks]

https://youtube.com/shorts/-O7guAoe1IE?feature=share

Hello! Can any fluent piggie speakers help me translate / understand a sound that one of our young boars makes please? This is a constant sound he makes whenever he's being handled, completely different to the chuttering they both do in the cage which I'd describe as a lowish pitched and happy "wut wut wut" sound.
This is more like a higher pitched twittering, it kind of sounds happy and yet nervous at the same time. His pal doesn't make this noise at all, he just mooches about with largely no sound at all.

Other than the nervous sound, he seems happy as Larry, so he feeds as normal, or often relaxes while he's stroked, all while making this sound.
Is he nervous perhaps?

 

[Wiebke]

He is a little apprehensive. This kind of constant juvenile squeaking update confers very much the emotional level; the bigger the intensity, i.e. quicker, higher pitched and louder it is, the higher is the stress/anxiety level.

 

[Canucks]

He is a little apprehensive. This kind of constant juvenile squeaking update confers the very much the emotional level; the bigger the intensity, i.e. quicker, higher pitched and louder it is, the higher is the stress/anxiety level.

Thanks Wiebke! That makes sense, it does "feel" like a nervous kind of sound.
Appreciate your input.