The sandworm is a native lifeform of the planet Arrakis. It lives in the vast sand dunes that stretch across the surface of the planet, and is a by-product of the same process that creates the Spice Melange. Sandworms typically stay beneath submerged in the sand, although occasionally they will surface. They are attracted to rhythmic vibrations, including human footsteps, which perturb them and will cause them to attack the source.