A sandworm is a fictional extraterrestrial creature that appears in the Dune novels written by Frank Herbert, first introduced in Dune (1965).
Sandworms are colossal, worm-like creatures that live on the desert planet Arrakis. Their larvae produce a drug called melange (known colloquially as "the spice"), the most essential and valuable commodity in the universe because it makes safe and accurate interstellar travel possible. Melange deposits are found in the sand seas of Arrakis, where the sandworms live and hunt, and harvesting the spice from the sand is a dangerous activity because sandworms are aggressive and territorial. Harvesting vehicles must be airlifted in and out of the sand sea in order to evade sandworm attacks. The struggle over the production and supply of melange is a central theme of the Dune saga. The sandworms are reverently called Shai-Hulud by the planet's indigenous Fremen, who worship them as agents of God whose actions are a form of divine intervention. The name is derived from the Arabic (šayʾ khulūd, "thing of immortality").
Conception
The sandworms in Dune were inspired by the dragons of European mythology that guard some sort of treasure. In particular, Herbert referred to the dragon in Beowulf that guards a hoard of gold in a cave, and the dragon of Colchis that guards the Golden Fleece from Jason. Like these dragons, the sandworms of Arrakis will attack anyone who attempts to take the treasure that is spice from the desert sands, as if they were guarding it. In Children of Dune (1976), a character even refers to sandworms as "the dragon on the floor of the desert." However, in the story, the sandworms are merely territorial and have no use for the spice, which is in fact waste matter produced by their larvae.
In the plot of Frank Herbert's novel Dune, Herbert used the sandworms (along with the spice they produce) as a plot device to provide Paul Atreides with the trials through which he ascends to a superhuman state of being. Herbert believed that a memorable myth must have something profoundly moving that could either empower the hero or overwhelm him completely. The force in question must be dangerous and terrifying, yet somehow essential. In Dune, the sandworms serve this function. To earn the spice, humans must cope with sandworm attacks on their harvesting expeditions. To earn an even greater prize (his apotheosis into the all-seeing Kwisatz Haderach), Paul undergoes even more dangerous and transformative trials in which he risks madness and death, one of which involves the ritual sacrifice of a juvenile sandworm, and another in which he must learn to ride a sandworm.
Sandworms are attracted to rhythmic vibrations in the sand, which they mistake for prey (smaller sandworms). To escape the notice of the sandworms, a traveller in the desert must learn to "walk without rhythm" in a manner that simulates the natural sounds of the desert. This element comes from Frank Herbert's experiences as a hunter and fisherman. He knew how to mask his presence from prey by techniques such as approaching from downwind and treading lightly. Frank Herbert's son Brian explained that "In Children of Dune, Leto II allowed sandtrout to attach themselves to his body, and this was based in part upon my father's own experiences as a boy growing up in Washington state, when he rolled up his trousers and waded into a stream or lake, permitting leeches to attach themselves to his legs."
John Schoenherr provided the earliest artwork for the Dune series, including the illustrations in the initial pulp magazine serial and the cover of the first hardcover edition. Frank Herbert was very pleased with Schoenherr's art, and remarked that he was "the only man who has ever visited Dune". Schoenherr gave the sandworm three triangular lobes that form the lips of its mouth. This design was referenced for the sandworm puppets that appeared in the 1984 movie adaptation of Dune.
Description Sandworms are giant creatures found only on the desert planet Arrakis. They are reverently called "Shai-Hulud" by the planet's indigenous Fremen, who worship them as agents of God whose actions are a form of divine intervention. The Fremen also refer to the sandworms as "Makers".
Physiology Herbert describes sandworms as colossal terrestrial annelids with features of the lamprey. They have an array of crystalline teeth which are used primarily for rasping rocks and sand. During his first close encounter with a sandworm in Dune, Paul notes, "Its mouth was some eighty meters in diameter... crystal teeth with the curved shape of crysknives glinting around the rim... the bellows breath of cinnamon, subtle aldehydes... acids..."
Sandworms grow to hundreds of meters in length, with specimens observed over longHerbert, Frank (1965). Dune. "Worms of more than four hundred meters in length have been recorded by reliable witnesses, and there's reason to believe even larger ones exist." and in diameter, although Paul becomes a sandrider by summoning a worm that "appeared to be" around half a league () or more in length. These gigantic worms burrow deep in the ground and travel swiftly; "most of the sand on Arrakis is credited to sandworm action".
Sandworms are described as "incredibly tough" by Liet-Kynes, who further notes that "high-voltage electrical shock applied separately to each ring segment" is the only known way to kill and preserve them; atomics are the only explosive powerful enough to kill an entire worm, with conventional explosives being unfeasible as "each ring segment has a life of its own".Herbert, Frank. Dune. "High voltage electrical shock applied separately to each ring segment is the only known way of killing and preserving an entire worm," Kynes said. "They can be stunned and shattered by explosives, but each ring segment has a life of its own. Barring atomics, I know of no explosive powerful enough to destroy a large worm entirely. They're incredibly tough." Water is poisonous to the worms, but it is in too short supply on Arrakis to be of use against any but the smallest of them.
Life cycle The sandworms of Herbert's Dune have a self-contained lifecycle and ecosystem with a feeding mechanism similar to how baleen whales feed on plankton. They move through the desert sands and ingest large quantities of melange pockets to consume the microscopic organisms known as "sand plankton" that inhabit it. These plankton eat melange which itself is a byproduct of dying sandworms. When consuming a melange mass, a sandworm excretes a more refined form of the melange as well as dispersing it across the desert environment, all this sustaining further plankton growth.
The "larval" stage of a sandworm are shown to be called "sandtrout", which the Fremen call "Little Makers". They are described as "flat and leathery" in Children of Dune, with Leto II noting that they are "roughly diamond-shaped" with "no head, no extremities, no eyes" and "coarse interlacings of extruded cilia". They can find water unerringly, and squeezing the sandtrout yields a "sweet green syrup". When water is flooded into the sandtrout's excretions, a pre-spice mass is formed; at this "stage of fungusoid wild growth", gases are produced which result in "a characteristic 'blow', exchanging the material from deep underground for the matter on the surface above it". After exposure to sun and air, this mass becomes melange.
While sandworms are capable of eating humans, the latter do contain a level of water beyond the preferred tolerances of the worms. They routinely devour melange-harvesting equipment—mistaking the mechanical rhythm for prey or a rival worm—but they seem to derive actual nutrition only from sand plankton and smaller sandworms, and have no actual interest in the spice. Sandworms will also not attack sandtrout.
Imperial Planetologist Pardot Kynes (father of Liet Kynes) had discovered the sandtrout during his ecological investigations of the planet, deducing their existence before he actually found one. Kynes determines that they block off water "into fertile pockets within the porous lower strata below the 280° (absolute) line", and Alia Atreides notes in Children of Dune that the "sandtrout, when linked edge to edge against the planet's bedrock, formed living cisterns".. The Fremen themselves protect their water supplies with "predator fish" that attack invading sandtrout. Sandtrout can be lured by small traces of water, and Fremen children catch and play with them; smoothing one over the hand forms a "living glove" until the creature is repelled by something in the "blood's water" and falls off.
Kynes' "water stealers" die "by the millions in each spice blow" and may be killed by even a "five-degree change in temperature". He notes that "the few survivors entered a semi-dormant cyst-hibernation to emerge in six years as small (about three meters long) sandworms". A small number of these then emerge into maturity as giant sandworms, to whom water is poisonous. A "stunted worm" is a "primitive form... that reaches a length of only about nine meters". Their drowning by the Fremen makes them expel the awareness-spectrum narcotic known as the Water of Life.
Leto II says in Children of Dune:
Behavior and function In Dune, the desert of Arrakis is the only known source of the spice melange, the most essential and valuable commodity in the universe. Used as a drug, melange lengthens life span, increases vitality, and heightens awareness. It can also unlock prescience in some subjects, which makes safe and accurate interstellar travel possible. The harvesting of melange is therefore essential, but is also a highly dangerous undertaking due to the presence of sandworms. Rhythmic activity as minimal as normal walking on the desert surface of Arrakis attracts the territorial worms, which are capable of swallowing even the largest mining equipment whole. They are an accepted obstacle to spice mining, as any attempt to exterminate them would be prohibitively expensive, if not entirely futile. Harvesting is done by a gigantic machine called a Harvester, which is carried to and from a spice blow by a larger craft called a Carryall. The Harvester on the ground has four scouting ornithopters patrolling around it watching for wormsign, the motions of sand which indicate that a worm is coming. Melange is collected from the open sand until a worm is close, at which time the Carryall lifts the Harvester to safety. The Fremen, who base their entire industry around the sale of spice and the manufacture of materials out of spice, have learned to co-exist with the sandworms in the desert and harvest the spice manually for their own use and for smuggling off-planet.
Due to their size and territorial nature, sandworms can be extremely dangerous, even to Fremen. The worms are attracted to—and maddened by—the presence of Holtzman force fields used as personal defense shields, and as a result these shields are of little use on Arrakis. In Children of Dune it is noted that a weapon has been developed on Arrakis called a "pseudo-shield". This device will attract and enrage any nearby sandworm, which will destroy anything in its vicinity. The Fremen manage to develop a unique relationship with the sandworms. They learn to avoid most worm attacks by mimicking the motions of desert animals, moving with the natural sounds of the desert rather than rhythmic vibrations. However, they also develop a device known as a thumper with the express purpose of generating a rhythmic vibration to attract a sandworm. This can be used either as a diversion or to summon a worm to ride.