"Centipedes and millipedes, the armored snakes of their size class, squeeze into the nearest crevices and wormholes. It may seem that the whole icky lot of them, and the miniature realism they inhabit are unrelated to human concerns. But scientists have found the exact opposite to be true. Together with the bacteria and other visible microorganisms summing and settled around the mineral grains of the soil, the ground dwellers are the heart of life on Earth. The terrain they inhabit is not just a matrix of soil and rubble. The entire ground habitat is alive. Living forms create virtually all of the substance that flow around the inert grains."