Crunching worms, squeaking voles, drumming ants: how scientists are learning to eavesdrop on the sounds of soil (thegaurdian.com) Until recently, soil had been a relative blank spot for monitoring species abundance. Farmers and gardeners hoping to find out how healthy their soils were had to dig up spadefuls and carry out laborious tests.Last year, a study found soil was the single most species-rich habitat on Earth, with more than half of all species living in it. But only a fraction have...