The Knife Song - Chop, Chop

This song has taken off among the kids - boys and girls - this week.  Some of them tell me they don't know the words but they do it anyway!  (I'm not sure it is necessary to know the words to be annoying.)  The kids do it before class, during class, while testing, etc.  What's the attraction??  I wonder how long it will last...   Oh, I should mention they use pencils instead of knives in class.  Some students have assured me, however, that they do use a knife when they are at home.  "Oh my!"  (There are other youtube clips with people going faster, but you can hear the words on this one.)