stool pigeon vs tattletale

stool pigeon

noun
  • An informer to the authorities, especially one who gives up criminal associates. 

  • A pigeon tied to a stool by a piece of twine, used as a decoy to entice free-flying birds to the ground to be shot or trapped. 

tattletale

noun
  • One who tattles (reports others' wrongdoings), often a child seeking attention. 

  • One who gossips, often for the sake of attention. 

verb
  • To act as a tattletale; to tell on; to give away, reveal, or expose. 

adj
  • telltale; giveaway 

How often have the words stool pigeon and tattletale occurred in a corpus of books? (source: Google Ngram Viewer )