I've been biten by hatchlings and by my kingsnake...
the hatchlings don't even make real contact, it's more like a pecking or nosing... but the kingsnake, that's another story... he clamped on and proceeded to enjoy the mock-meal until I could figure out how to get him off without hurting him.
The first time he bit me was when he was only a few months old.. I didn't even know he had bitten me until I moved my hand and he was still hanging there...
now that he is a bit bigger it does sting a bit but he doesn't just tag and let go, he gets a grip and hangs on... he can be a mean little bugger! he brought blood the last time, but it wasn't like a cut or anything it was like everyone else stated... more like pinholes... and I seem to remember it burning/stinging more than hurting...
I agree with everyone else.... I think it's more the shock factor than the bite itself...