"nipper" for child

I've just found a passage in Peter Ackroyd's London biography (apologies in advance - I just keep finding interesting tidbits)quoting a seventeenth century city recorder who was giving evidence about a raid on Watton's Ale house in Billingsgate. Apparently the inn keeper was running a sort of school for child pick pockets. It really could have come directly from Oliver Twist. "Pockets and purses were hung upon a line with 'hawkes bells' or 'scaring bells' attached to them; if a child could remove a coin or counter without setting off the bell 'he was adjudged a judicaill Nypper'".

So I'm guessing this is the origin of calling children "little nippers".

"Nipper" was the OED's Word of the Day a few months ago. I didn't copy it, but the 1st ed. has these definitions, among others:
(Cant) A thief or pickpocket. Obs.
A boy who assists a costermonger, carter, or workman.
A boy, a lad.
(Earliest quotations for these three senses are in chronological sequence.)

I guess the name arose because small children tend to dash here and there quickly - they are 'nippy', hence the noun 'nipper' for a child/youth.