Digworms are molted in shades and markings of black, purple, blue, and pale yellow. Their torpedo-shaped bodies enable them to burrow and travel under sand. Two triangular-shaped fins steer and balance the digworm when entering and exiting the sand. A digworm’s body is covered with long, sensitive spines that sense vibrations. The wide mouth has sharp, curved teeth for grasping prey and preventing their catch from escaping while the digworm swallows.
The terrestrial digworms prefer deep sandy landscapes, such as coastal beaches along floodplains. Digworms can lie dormant underground for many months without food.
Digworms are ferociously aggressive predators, ambushing large creatures such as beachcombers. The sensitive spines of a digworm pinpoint the location of prey as it moves on the surface above. Once in position, the digworm ambushes its prey by erupting from the ground and grabbing the victim with its teeth. Digworms will subdue large prey by thrashing them repeatedly before swallowing them whole.
Digworms are hermaphroditic, meaning that each individual produces sperm and eggs. A digworm can fertilize its own eggs but usually exchanges sperm from a mate. Rarely, a digworm will cheat by fertilizing another digworms eggs without using any of the sperm given in return. In this way, a digworm can fertilize its own eggs and the eggs of other digworms at the same time. Digworms lay up to 30 eggs inside a shallow tunnel in the sand. The young, which resemble adult digworms except smaller in size, can hunt their own prey after hatching.
Digworms occasionally practice cannibalism, in which a large digworm consumes a smaller digworm encountered underground. Cannibalism might be driven by a digworm’s need to accumulate rare minerals in its skin, which can be more easily obtained from other digrwoms than from typical prey.