Diplopoda is a class of arthropods commonly known as millipedes. They are characterized by their elongated bodies, which typically have two pairs of legs per body segment, giving them a distinct appearance. Millipedes are primarily detritivores, feeding on decaying plant material, and play an important role in soil health. These creatures are usually found in damp environments, such as forests and gardens, where they help decompose organic matter. While millipedes are not harmful to humans, some species can secrete toxic substances as a defense mechanism against predators.