They fold their leathery wings by day, hanging by hook-like claws high in the rafters. They rest unseen behind grand gilded bookcases until dusk when they come out to feast.
They are bats in the library—waiting till dark to snatch up the bugs that else would feed upon the priceless books in keep.
As people file out of the 300-year-old Baroque building, at evening, the staff of the Biblioteca Joanina know to expect them. In fact, for centuries, the bats have tackled an essential role in the library, that being pest control for what has been called one of the world’s most beautiful libraries.
You won’t see them during visits, though.
On arriving at Portugal’s University of Coimbra, the home of Biblioteca Joanina, tourists will be wowed by the interior all ablaze with gorgeous 18th-century decoration on first entering from the old cobblestone square of the Palace of Schools. They will have passed the statue of the library’s founder, King John V of Portugal, after whom it was christened.
![Exotic wood tables are covered in large leather sheets at night to protect them from bat droppings. (agsaz/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693131-93-45345-library-bats-portugal-53453549568.jpg&w=1200&q=75)
![A colony of bats is said to live behind the bookcases in the Biblioteca Joanina. (Martin Lehmann/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693128-93-45345-library-bats-portugal-59568-4568.jpg&w=1200&q=75)
![A common pipistrellus bat. (Corina Daniela Obertas/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693130-93-45345-library-bats-portugal-595934568.jpg&w=1200&q=75)
The Age of Enlightenment was dawning when its building began in 1717. The construction was finally done in 1728. The first books arrived in 1750, and now the library holds some 70,000 volumes that focus on science, civil and canon law, philosophy, and theology, and some date back as far as the 15th century. The volumes were said to represent the best of what was printed across the continent.
![The main entrance to B<span class="mw-page-title-main">iblioteca Joanina from the square of the Palace of Schools at the University of Coimbra, Portugal. (rui vale sousa/Shutterstock)</span>](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693124-93-45345-library-bats-portugal-345345934568.jpg&w=1200&q=75)
![A view from the direction of the main entrance looking inside the B<span class="mw-page-title-main">iblioteca Joanina. (Benny Marty/Shutterstock)</span>](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693127-93-45345-library-bats-portugal-345958-345934568.jpg&w=1200&q=75)
When you enter from the square, you actually stand on the third and highest floor of the biblioteca, called the Noble Floor, richly adorned. Here stand those grand gilded bookshelves. The three halls of this floor are separated by lofty and ornamented arches and are filled with shelves of exotic, multi-colored oak wood. Precious, tropical woods from Brazil tell of Portugal’s imperial past glory.
The teak front doors shut the whole structure like a vault that holds a treasure. Stone walls over 2 meters thick help regulate the temperature and humidity for the conservation of the antique volumes stored within.
There are two lower floors, of course, but as now we speak of conservation, there are those furry flying mammals to mention.
![Ornate balconies and furniture inside the Noble Room. (agsaz/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693136-93-45345-library-bats-portugal-59568.jpg&w=1200&q=75)
![The Noble Room features a central portrait of King John V of Portugal. (Sopotnicki/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693133-93-45345-library-bats-portugal-3458-345934568.jpg&w=1200&q=75)
While the scent of the oak wood engenders a natural insect repellent, these bats are far more efficient at it. They possess a voracious appetite for insects that love to nom through paper books and manuscripts. But perhaps the bugs they love the most are mosquitoes. The staff prefer the nuisance of the bats who hunt the pests to the task of dealing with said pests themselves.
The only real worry is bat droppings.
In time-honored fashion, staff know to cover the luxurious credenzas with vast sheets of leather as protection from the mess. In European libraries and churches, over centuries, this has proved the way to go. Come morning, staff remove the sheets and spend a little elbow grease buffing out the marble floor where droppings fell.
It’s a small price to pay for the protection of priceless volumes.
![A ceiling fresco depicts an allegory handing books, symbolizing knowledge, to the four corners of the world. (Benny Marty/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693134-93-45345-library-bats-portugal-3459568-345934568.jpg&w=1200&q=75)
The colony of bats has been a fixture of the library from nearly as early as when King John V first built it—perhaps as early as when his portrait hanging opposite the teak front door was still fresh. Perhaps the frescos still were fresh when the bats flapped under them, those scenes depicting allegories in bright hues:
A central female figure on the ceiling holds a book, a symbol of knowledge passed on to the four corners of the world: Europe, America, Asia, and Africa.
After marveling at the two-story gilded shelves and ornate arches donning crests; after examining the six embossed tables of wood and the verandas of rich carvings and gold; not to mention the secret stair hidden in a false wood arch painted to look like marble, a secret door known to only staff that leads up to the balcony, off limits to visitors; then we may head down the stairs.
![B<span class="mw-page-title-main">iblioteca Joanina </span>is considered one of the world's most beautiful libraries. (Benny Marty/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693137-93-45345-library-bats-portugal-345958-34934568.jpg&w=1200&q=75)
![An exterior view of the Biblioteca Joanina, showing the lower levels. (rui vale sousa/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693140-93-45345-library-bats-portugal-59568-345934568.jpg&w=1200&q=75)
The Middle Floor is more austere, carved of plain stone masonry. It may sound strange, but guards and watchmen long ago were stationed here. Until 1834, the university was a self-governing body, and thus it maintained its very own Royal Palace prison. Hard to access years ago, now it’s open to show off manuscripts and also serves as a place to conserve.
A medieval prison sits at the structure’s very base. Narrow cells and a winding stair constitute a prison of primitive means, the oldest preserved in Portugal. On ground level, it now serves as a book deposit store where collections were brought to be cataloged before being shelved on the main floor.
![The Middle Floor features rough-cut masonry. (trabantos/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693139-93-45345-library-bats-portugal-59234568.jpg&w=1200&q=75)
![The Middle Floor of Biblioteca Joanina was said to have stationed watchmen when the library housed the university's own prison. (agsaz/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693141-93-45345-library-bats-portugal-59435568.jpg&w=1200&q=75)
![Biblioteca Joanina. (trabantos/Shutterstock)](/_next/image?url=https%3A%2F%2Fimg.theepochtimes.com%2Fassets%2Fuploads%2F2024%2F07%2F24%2Fid5693142-93-45344565-library-bats-portugal-59568.jpg&w=1200&q=75)
Each year, half a million come to Biblioteca Joanina, which is the real reason why conservation is so meticulous. Traffic tracks in heaps of dust and changes the environment. Only 60 people now are allowed to enter every twenty minutes to keep preservation under reign. They can’t stay in the main room for longer than 10 minutes.
Meanwhile, the small army of creatures that live behind the bookshelves continues to wage a war of pest control. The colony of bats has stayed essential over the years and continues to contribute their part.