Tiny mites fossilised in mud at the bottom of a sacred Peruvian lake have helped to develop our understanding of the rise and fall of the ancient Inca empire.
The numbers of mites found in mud cores, which fed on excrement, have helped determine the trade routes used by llama caravans and show the wane of the Inca empire with the arrival of the Spanish. They also indicate the introduction of domesticated animals, such as sheep and cattle, in the 16th century.
The research, by authors including Sussex University's Michael Frogley, is published in the Journal of Archaeological Science this month. It is hoped that the technique of counting mites can be applied to understanding the human impact on the environment elsewhere.