The Unwitting Archaeologists
On the arid "Black Hill," or Karatepa, near the city of Termez, lies a sprawling Buddhist monastery complex that flourished between the 2nd and 4th centuries AD. This important site from the Kushan Empire, covering over seven hectares, consists of dozens of temples, stupas, and monastic cells, many of which are subterranean caves carved directly into the sandstone hills. While human archaeologists have been excavating Karatepa since the 1920s, they have some unusual assistants: termites.
The region hosts several species of harvester termites, primarily from the genus Anacanthotermes. These insects are known for their extensive underground colonies and foraging activities. One species, Anacanthotermes ahngerianus, builds conspicuous mounds that can reach up to 70 cm in height and 2 meters in diameter. In a process known as bioturbation, the termites excavate soil particles from deep within the ground to construct and maintain these mounds. As they tunnel through the stratified layers of the archaeological site, their activity brings small, durable artifacts to the surface and deposits them on the exterior of the mounds. This constant, slow-motion excavation provides a steady stream of material from buried cultural layers.
A Non-Invasive Technique
Archaeologists have learned to harness this natural process. Instead of digging traditional excavation pits, which is a destructive process, researchers can systematically collect the artifacts deposited by the termites. By carefully mapping the location of each find on the surface of the mounds, they can create a "virtual excavation." The theory is that material brought up from the deepest archaeological layers will be deposited lower on the mounds, while artifacts from shallower, more recent layers will appear higher up. This allows for a preliminary reconstruction of the site's stratigraphy without disturbing the ground.
The objects unearthed by the termites are small but informative. They include thousands of tiny fragments of pottery, pieces of glass vessels, beads, and slag from metalworking. These finds help to date the various periods of occupation at the monastery complex. For instance, the discovery of Soter Megas coins helped to date the construction of some of the earliest monastery structures to the latter half of the first century CE. The analysis of these insect-retrieved artifacts complements the larger-scale excavations, providing data from across the 7-hectare site and helping to identify areas for more focused investigation. The finds confirm Karatepa's position as a major Buddhist center on the Silk Road, with inscriptions found on pottery and walls in multiple scripts, including Bactrian, Kharosthi, and Brahmi.