Amazing Places

These Baroque Portuguese Libraries Employ Bats for a Very Important Purpose

Books are delicate things. They're sensitive to heat, moisture, and light. Worst of all is probably pests. You've got to keep your books safe from nibbling mice, burrowing bookworms, and cover-chomping moths. But you might be surprised to learn that at some libraries, pest control is a matter of fighting fire with fire. These Portuguese libraries are home to multiple colonies of bug-eating bats.

University Library in Coimbra

Quick, to the Bat-Library!

You could be forgiven if the bat-infested library you're imagining is straight out of the Addams Family mansion. Although the libraries at the University of Coimbra and the Palace of Mafra are probably ornate enough for Gomez and Morticia, they're also a tad on the colorful side. That's because both were built in heavily adorned baroque style, and the one at the palace was plastered in even more elaborate rococo ornamentation. Their bats and their ostentatious aesthetic aren't the only things the libraries share, either — both were built in the 18th century, both are in Portugal, and experts at both have only a hazy idea of where the bats came from in the first place.

All agree, however, that the bats play a vital role in keeping the books safe. Thanks to these furry permanent residents, the libraries are both protected from insects and bookworms. Those high ceilings and elaborate adornments make for a perfect place for bats to nest during the day, and at night, they emerge to satisfy their prodigious 500-bug-a-day diet. Of course, that comes with its own perils, and both libraries must also take steps to clean the bat droppings every single morning.

Library of the Mafra National Palace

Bats from the Past

The library at the university, called Biblioteca Joanina after the king at the time it was built, wouldn't trade the bats for anything, even if guano is a problem. They're basically built into the library's identity at this point, anyway. As director Carlos Fiolhais told Signs of the Times, "Bats have been living in the library since ever. The library tables are protected with [animal] hide every night, because they are also antiques and the bats fly freely, eating the bugs." In fact, that hide is proof of how old the library's bat colony is. Records dating back 200 years show orders for those exact same cuts of hide. These bats have been here for a while.

These two batty bibliotecas are just the beginning when it comes to strange and wonderful libraries. Check out James W.P. Campbell's book "The Library: A World History" to discover the thousands of mind-blowing ways human beings have preserved knowledge for generations to come. If you decide to buy the book through that link, Curiosity will receive a portion of the sale — and we really appreciate it.

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Written by Reuben Westmaas May 15, 2018