have bats in one's belfry
To be crazy or eccentric.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He has bats in his belfry if he thinks that will work.”
“You have bats in your belfry if you want to skydive without a parachute.”
“She thinks I have bats in my belfry because I prefer eating dessert for breakfast.”
“Everyone thinks the old man has bats in his belfry because he talks to his garden plants every morning.”
“My neighbor definitely has bats in her belfry because she wears a winter coat and heavy boots to the beach in the middle of July.”
“The inventor clearly has bats in his belfry since he spent his entire life savings trying to build a machine that turns lead into gold.”
“While his colleagues dismissed his radical theories as evidence that he had bats in his belfry, he remained convinced that his unconventional approach would eventually yield a breakthrough.”
first recorded 19th c.
First appearing in 1899, the phrase relies on the erratic, fluttering flight of bats to illustrate mental instability. The term belfry serves as a metaphor for the human head or mind, suggesting that a person’s thoughts are as disordered as a colony of bats disturbed within a church tower.
- 01
abound in one's own sense
To follow one’s own inclinations and opinions.
- 02
ace up one's sleeve
A surprise advantage of which others are not aware.
- 03
act one's age
To behave in a manner appropriate to one's age.
- 04
act one's age, not one's shoe size
Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).
- 05
afraid of one's own shadow
Exceptionally timid.
- 06
air one's dirty laundry in public
To reveal one's sordid secrets to the public.
- 07
air one's dirty linen in public
Synonym of air one's dirty laundry in public.
- 08
albatross around one's neck
A characteristic, possession, associate, or previous deed that hinders one's ability to succeed.
Last updated August 10, 2026