pitter-patter vs tattoo

pitter-patter

noun
  • A soft, percussive sound, as of tiny feet, or of rain on a rooftop. 

tattoo

noun
  • A signal played five minutes before taps (lights out). 

  • A signal by drum or bugle ordering soldiers to return to their quarters. 

  • A military display or pageant. 

  • A pony of a certain breed from India. 

  • An image made in the skin with ink and a needle. 

  • A method of decorating the skin by inserting colored substances under the surface with a sharp instrument (usually a solenoid-driven needle). 

verb
  • To hit the ball hard, as if to figuratively leave a tattoo on the ball. 

  • To tap rhythmically on, to drum. 

  • To apply a tattoo to (someone or something). 

How often have the words pitter-patter and tattoo occurred in a corpus of books? (source: Google Ngram Viewer )