English: Silex spring in Yellowstone National Park.Hot water is a better solvent than cooler water; it dissolves large amounts of silica, the major element of these volcanic rocks. Silica, in the form of sinter, lines the bottom of Silex spring. It forms terraces along the runoff channels and gives the spring its name: Silex is Latin for silica.Silex Spring overflows most of the year. This overflow creates a hot environment where thermophiles thrive. Thermophiles become food for several kinds of flies that live in and on the hot water. The flies then become food for mites, spiders, various insects and birds