Scientists believe the new coronavirus Sars-Cov-2 may have originated in bats before somehow jumping to humans.
Bats are known to be reservoirs of viruses that affect humans, so studying them can give us important clues about how to fight new ones.
The BBC joined a group of scientists at the Khao Ang Rue Nai wildlife sanctuary in Chachoengsao, Thailand, as they collected samples from bats. They say there is nothing to fear but much to learn from the little animals.
Filmed and produced by Danny Bull, Thanyarat Doksone and Miho Tanaka
Covid-19 (Coronavirus) news from BBC