There may be some truth in the Pied Piper story.  See http://www.timesonline.co.uk/tol/news/world/europe/article7139575.ece.  At certain points in the late Middle Ages, there were companies of mercenaries, pilgrims and traveling musicians (who could have learned to play something like a bagpipe since they came to Europe via the Crusades).  A piper (who played a larger bagpipe) would have been likely to travel with a mercenary band. It is certainly possible that someone learned this trick with rats and bagpipes and used it to his financial advantage.  It might be possible that he or his mercenary buddies took the children in the town to use as “recruits” much as the armies do in Africa. Of course, this is total speculation, but it seems to be the simplest solution to me.This would not be the only instance where this was done.  The Russian army took Jewish boys at age 12 (before the Bar Mitzvah).  Most boys taken that way never returned - this was one reason for some of the mass emigrations during the mid to late 1800's; also one reason for the many Jewish boys who played instruments, which was partly to gain entrance into a gymkhana - which in turn exempted boys from military service.