Oh my goodness...2lbs....soooo teensy!!!
Sounds to me like he's doing what he'd do to his 'fur' mummy when he's winding down, getting ready for sleep, kind of pretend suckling....
Totally agree with Jkpal....do they make a 'puppy sucking/nibbling comforter'? Probably!
Oh, and welcome to YT - happy to meet you both!
Sally + Harry
xx