Every night, silent “employees” sweep through a historic library, guarding books without fail.
They never clock in, never ask for payment, and have occupied these stacks for over three centuries. Visitors walk through the iconic halls, unaware of the strange preservation work taking place in the shadows.
Once the doors lock, their shift begins using methods as effective as they are bizarre.
Who are these employees and how do they protect the books?
The 300-year shift: The secret guardians of Portugal’s Baroque library
The 300-year-old Joanina Library in Portugal is a preserved relic of a bygone era.
Golden shelves, ancient carved wood, and historic manuscripts fill the library.
It is almost frozen in time, untouched by centuries of human evolution. However, something in the library is very much alive, even if it is invisible.
The library houses a world of ancient information dating back several centuries.
Many are vulnerable to a silent yet persistent threat. Microscopic insects can destroy entire collections in the silence of the night.
And once that starts, it can spread rapidly through the historic books and manuscripts. Conventional methods rely on chemicals to control the problem.
But this library relies on something far older, and even stranger. What has been protecting this library for centuries?
A hidden threat that never lets up
Older books are especially attractive to insects.
And these bugs could become the next nightmare for humanity, or at least our historical records.
Books contain organic material like paper, leather, and even starch-based adhesives.
To some insects, they are a consistent and reliable source of food. Left alone, insects can quickly destroy entire collections.
In most other libraries, preventing this requires almost constant monitoring.
Humidity levels need to be controlled, and chemicals may be needed. Even then, insect infestations can still occur.
The Joanina Library faced this same issue long, long ago. Its huge collection of ancient books was especially vulnerable.
And it came up with a unique solution to the problem.
It required no additional climate control or chemical applications. Only an iconic creature.
Mother Nature provided everything the library needed.
One animal prevented an invisible crisis, and it certainly was not intending to do so.
It was merely following instincts and feeding on the insects.
Which animal? The University of Coimbra has explained.
Silent “employees” who saved some of our most treasured texts
The library opted to “employ” a colony of bats to keep the insects at bay.
Some animals can play a vital role in humanity and our ambitions.
At the Joanina Library, the bats emerged from hidden crevices within the building.
They silently fly through the library, feeding on the destructive insects. Acting as a natural form of pest control.
Nature’s non-invasive archivists: Preservation without destruction
The bats consume moths, beetles, and other insects that feed on the books. This unique animal-human relationship has stood the test of time.
Naturally, their presence does require small adjustments. Staff developed a regular routine. They covered tables with protective cloths each evening before locking up.
Conservation methods like this are unique. Taking place over hundreds of years.
Most never reach this level of longevity, despite new technology.
The bats never asked for pay, formed a union, or even complained once. They simply followed their natural instincts.
The silent and hidden army of critters has saved significantly important ancient texts.
The world is obsessed with the latest high-tech solutions. But could the most sophisticated preservation tool actually be the one that’s been hiding in the rafters all along?