The sloth is so named because of its very low metabolism and deliberate movements, sloth being related to the word slow. This is an evolutionary adaptation to their low-energy diet of leaves, and to avoid detection by predatory hawks and cats who hunt by sight. Sloths are almost helpless on the ground but are able to swim. The grooved hairs of the sloth's shaggy coat is a host to symbiotic green algae which helps the sloth camouflage itself in the trees, and provides nutrients to the sloth.
