RichThesaurus
have bats in one's belfry
vs
have bats in the belfry
have bats in one's belfry
verb
To be crazy or eccentric.
have bats in the belfry
How often have the words
have bats in one's belfry
and
have bats in the belfry
occurred in a corpus of books?
(source:
Google Ngram Viewer
)