butcher boy vs pill bug

butcher boy

noun
  • A woodlouse, any of various terrestrial crustaceans of the suborder Oniscidea. 

  • A male prostitute. 

  • Batting at a pitch with a short swing from a bunt position; a slash bunt, a slug bunt. 

  • A man or boy who works for a butcher shop; a butcher's boy. 

pill bug

noun
  • Any of very many terrestrial crustaceans, of the family Armadillidiidae, a subgroup of the woodlice, that can roll themselves up into a protective ball. 

How often have the words butcher boy and pill bug occurred in a corpus of books? (source: Google Ngram Viewer )