pat down vs pick at

pat down

verb
  • To frisk; to check someone's body for concealed items, especially weapons. 

pick at

verb
  • To touch, grab, handle, or pull tentatively or gingerly, using a utensil or one's fingers. 

  • To pick on or repeatedly criticize (someone). 

How often have the words pat down and pick at occurred in a corpus of books? (source: Google Ngram Viewer )