go bananas vs have bats in one's belfry

go bananas

verb
  • To become silly or excited; to go crazy. 

  • To get angry; to go mad. 

have bats in one's belfry

verb
  • To be crazy or eccentric. 

How often have the words go bananas and have bats in one's belfry occurred in a corpus of books? (source: Google Ngram Viewer )