From the Times Online: Dung-eating mites throw light on Inca civilisation.

Mites that eat llama dung are providing scientists with critical new clues to the rise and fall of the Inca empire and the civilisations that preceded it.

The soil invertebrates are allowing researchers to trace the growth and decline of the peoples of the Andes several centuries before the Spanish conquest in 1532 brought written records to the region for the first time.

The evidence gleaned from fossilised mites, preserved in sediments at a lake about 50km (30 miles) from the Inca capital of Cuzco, has shown how the great empire increased in size and complexity in the early 15th century.

The abundance of the fossil mites is directly linked to the amount of llama dung that was deposited on the pastures around Lake Maracocha at particular times, and can thus be used as a proxy for estimating the size of the herds and pack trains that grazed there.

From this a team led by Alex Chepstow-Lusty, of Montpellier University in France, has been able to reconstruct the fluctuating fortunes of local populations for an era from which no written records exist. [continue]