When archaeologists recently excavated the ceremonial entranceway to an ancient palace in Peru, they were excited to discover a series of 750-year-old wooden “guardians” flanking the passage. But there was an even bigger surprise in store as the statues emerged from the dirt: termites had chewed through the 19 wooden bodies over the centuries, leaving in their place two-foot-high human figures fashioned at least partially—and in some cases perhaps almost completely—from centuries-old insect excrement.

Not all the statues received the same termite “treatment,” says archaeological director Henry Gayoso. Upon initial inspection, some of the statues appeared to consist almost completely of termite excrement (formally known as frass), Gayoso told National Geographic in an email. Others seemed to have the wooden