budgie nibbling and snuggling

Question
I've added a new budgie to my flock and he's currently in quarantine from my other birds. I've had him for 4 days now and I think he's about 10-12 weeks old.
He's already extremely tame and has started hopping out of his cage onto my hand in just a couple of days.

My first question involves his want to literally snuggle with me.  He throws tantrum when I put him back in his cage & tries to get out and paces back and forth until he finds something else to do or until I take him out of his cage again.  When he's out of his cage, he mostly just wants to hang out with me.  Today he spent several hours total just snuggled up in my hand or in my jacket nestled against my chest.  I love that he's snuggly, but is this normal?

Also, when he's pacing back and forth in his cage, if I put my hand in palm up he jumps into it and starts nibbling all over my hand.  I don't mind it but every once in a while he'll really clamp down and it really hurts!  What is this behavior?  He's obviously not scared of me at all and he's obviously very comfortable with me in general. I am just confused as to why he would occasionally bite hard if he's not threatened.
Thank you!

Answer
This sort of behavior is normal.  It could be just affection, or he may have chosen you as a mate, as strange as that sounds.  Sometimes if male budgies don't have a mate, especially younger budgies that tend to get hormonal, will bond with their handlers like they would another budgie.  Pacing is a way of getting a female's, or in this case your, attention.  He may or may not grow out of this, but don't worry.  He'll still stay very affectionate, he'll just eventually come out of this breeding phase.

Nibbling or biting is a sign of affection.  Budgies don't seem to mind it most of the time.  Even though it hurts, he doesn't see it that way.  He's trying to be sweet.  What I usually do when my budgies bite is wrap my fingers, or wherever they are deciding to bite, in band-aids.  It keeps them from getting a very good grip to bite you, and keeps it from hurting as much.

Good luck with your cuddly little friend!