Fun read from Smithsonian Magazine on the how bats have taken up residence in some Portuguese libraries, and why the bats are being welcomed with open arms.

At the University of Coimbra in central Portugal, there are bats in the biblioteca. They swoop through the stacks, winging over a first-edition of Dionysius of Halicarnassus’s “Roman Antiquities” and past a 15th-century book of hours and Homer’s “Opera Omnia” — snapping up bugs as they go.

It’s one of two 18th-century Portuguese libraries where bats are welcome guests, allowed to stay for the bug-eating — and, by extension, manuscript-preserving — services they provide. And visitors to Portugal can see them for themselves.

In Coimbra, a colony of Common pipistrelle bats makes their home behind the bookshelves of the university’s Joanina Library, emerging at nightfall to consume flies and gnats and other pests before swooping out the library windows and across the hilltop college town in search of water. The service they provide is indispensable: They eat insects in the library that might otherwise feed on manuscript pages.

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