THE GREATER HORSESHOE BAT, which inhabits belfries, derelict building and caves. It has powerful teeth for crunching the tough shells of beetles, and a wing-span of up to 14 ins. Here it is seen sleeping.
                                                              (Photograph by J. H. D. Hooper.)

from Sport & Country (London) – 7^th February 1951

 

 

The phrase to have bats in one’s belfry and variants mean to be crazy or eccentric.

B. A. Phythian explained, in A Concise Dictionary of Phrase and Fable (London, 1993):

The comparison is between the head and the upper part of a church: the belfry is the brain; the bats clutter it up or flutter around when disturbed by the bell, like confused thoughts in a disordered mind.

(The equivalent French expression is avoir une araignée au plafond, literally to have a spider at the ceiling.)

Of American-English origin, to have bats in one’s belfry seems to date back to the late 19^th century: the earliest instances that I have found are from 1897. For example, the following is from The Paducah Daily Sun (Paducah, Kentucky) of 9^th November of that year:

CHARGED WITH LUNACY.
Jane Jones Seems to Have Bats in Her Belfry.
Constables Patton and Futrell Have a Time Taking Her.

Jane Jones, colored, who stood guard over the putrid remains of her daughter, Ella Jones, at her home on South Fourth street yesterday, and would not suffer them interred until Coroner Nance went to the house with a police officer, to enforce a burial, was arrested this morning by Constables Patton and Futrell on a writ of lunatico inquirendo and taken to the county jail. The aged woman evidently “has bats in her belfry,” and will be tried before Judge Bishop at 3 o’clock this afternoon.

The following from The Globe (London) of 15^th December 1903 shows that the phrase was not in use in Britain at that time:

The lively remarks of Mr. Frederick Manley, of Harvard University, on the subject of American slang will confirm many people in their opinion that such slang is not wholly a bad thing. Vulgar as much slang is, there can be no doubt that many expressions which would not be used by precise people contain a wealth of imagery, and add a colour to everyday speech. Among other examples, Mr. Manley cited the phrase, “having bats in one’s belfry,” which an American uses where a Briton would state that his head was swimming. Such a phrase is almost poetic.

In 1907, the American author Ambrose Bierce (1842-circa 1914) had a column titled Small Contributions in Cosmopolitan Magazine (New York). In the July issue, he wrote Some Sober Words on Slang, containing the following:

Grave advocacy of slang is not lacking. It is not long since a learned professor in one of our universities uttered the solemn intimation that if the author of the Scriptures had lived in our time he would have substituted for certain admired expressions expressions more admirable from the vocabulary of slang, which the more fortune-favored writer had the goodness to point out. He was especially charmed with the phrase “bats in his belfry,” and would indubitably substitute it for “possessed of a devil,” the Scriptural diagnosis of insanity.

The adjectives bats and batty, of same meaning, probably derive from to have bats in one’s belfry, although I have discovered an instance of batty that slightly predates the earliest use of the phrase that I have found; The Brooklyn Daily Eagle (Brooklyn, New York) of 27^th December 1893 mentioned “this little wrangle […] that enlivened the proceedings at the meeting of the Twenty-sixth Ward Republican association committee […] last evening”:

“Don’t get batty.”
“I’ll get just as batty as you are.”
“You will?”
“Yes, I will.”
“Order! Order!”
“Well, he can’t bulldoze me, Mr. Chairman. I’ll stand up for my rights.”
“Sit down.”
“Shut up.”