Ants and termites could be pressed into service as tiny gold miners, say researchers, who have found them excreting miniature nuggets in their mounds.
Analysis of termite mounds at a test site in the West Australian goldfields showed high concentrations of gold, giving a pointer to the larger deposits beneath.
"We're using insects to help find new gold and other mineral deposits," says CSIRO entomologist Dr Aaron Stewart - who can surely never have expected his speciality to be quite so lucrative.
"These resources are becoming increasingly hard to find because much of the Australian landscape is covered by a layer of eroded material that masks what's going on deeper underground."
But termites and ants burrow down into this layer, and bring traces of gold to the surface.
"The insects bring up small particles that contain gold from the deposit's fingerprint, or halo, and effectively stockpile it in their mounds," says Stewart.
"Although the insects may not concentrate metals in their bodies, they actively rid their bodies of excess metals. This process shows up as little stones, much like kidney stones in people. This finding is important because these excretions are a driving force in redistribution of metals near the surface."
After 150 years of mining in Australia, pretty much all the gold near the surface has been discovered. Insects, says Stewart, could make for a low-cost and environmentally friendly alternative to drilling.