PHOTHARAM, Thailand — The bat caves reeked of bat.
In the murk of the grottoes, in a cave complex west of Bangkok, Thais in headlamps and with flashlights went about their business.
Pilgrims to the temple that owns the complex prayed to Buddha figurines in one of the caves, the statues’ carved expressions betraying no reaction to the plip-plop-ploop of bat droppings falling on their shoulders.
Collectors of bat dung, or guano, scraped up the droppings to sell as fertilizer, hefting bags of manure through an obstacle course of stalactites and stalagmites.
And medical researchers, overseen by one of the world’s foremost bat virologists, trapped the winged mammals to test them for traces of the coronavirus that causes Covid-19. Scientists believe it originated in bats.
Outside the complex, the abbot of the Buddhist temple, which calls itself the “temple of hundreds of millions of…
