An arthropod (class Diplopoda) with a segmented body, each segment being formed from two fused segments, and each double-segment bearing two pairs of legs. Millipedes thus have many legs, but despite their name none has 1000. They range in size from about 1.5 to 38 cm. Millipedes move slowly through the soil feeding on detritus and fungi, some on plant fluids, and a few are predators. Most defend themselves by rolling into a ball. There are about 10,000 species found worldwide, but most are in the southern hemisphere.