Round Worms are slender worms with tapering ends. They are usually about 1mm in length. They are found almost everywhere: they live in soil, ocean water, and inside or outside most small animals. Round worms have muscles that are under the skin along side of the body. It lies just underneath the epidermis, which is essentially the skin of the worm. Round worms do not have muscles that allow them to lift itself up or crawl, but they move from side to side. This is their only way of movement.