Bizarre Alien Senses

"I have eight other senses; but I'd give them all up, even smision, just to experience taste."

- Bender, Futurama

One way to make an alien creature seem bizarre to human audiences is to have it detect the world around it with a different array of biological senses than us. Often they're depicted as using sensory mechanisms found in other Earth species, such as echolocation, thermographic vision, or sensitivity to electrical impulses or vibrations. More rarely, writers will equip aliens with biological versions of radar or other technological sensors, or they'll invent senses that discern esoteric forces such as psychic energy.

Senses that are found in we humans are often absent or much-reduced in beings equipped with bizarre alien senses. On film, this trope may be depicted with Point of View shots using image-distorting or false-color effects. Most commonly seen in Science Fiction, but occasionally in other Speculative Fiction genres.

A subtrope of Bizarre Alien Biology. Frequently correlated with Eyeless Face. Contrast Blindfolded Vision, in which someone denied their normal eyesight relies on other sensory modes, or Super Senses, when normal human senses are enhanced. For a different sort of alien feeling, see Inhuman Emotion.

Comics

 * In the "vegetable sex" scene from Saga of the Swamp Thing, Abigail temporarily experiences Swamp Thing's ability to sense life force, and perceives the wetlands as a shimmering field of glowing vegetation, dotted with bright life-sparks of animals.

Film

 * The ravenous flying beasts from Pitch Black use echolocation, which is depicted on-screen as textured pixel-clouds that take on the shapes of objects.
 * In the Tremors franchise, Graboids pinpoint their prey using sound and other vibrations, while Shriekers and Ass-Blasters use heat vision that's enhanced by blasts of heat emanating from their mouths.
 * In the Predator film series, the title aliens have infrared vision. This is depicted onscreen by coloring what they see based on the temperature of objects: black = cold, white = hot, and other colors in between.
 * Wolfen was probably the first film to incorporate thermographic footage to represent this trope.

Literature

 * The life forms of Darwin IV, from Wayne Barlowe's Expedition, lack eyes and rely on a combination of sonar and thermographic senses to discern their environment. Justified as a consequence of Darwin IV's having been extremely foggy in the recent evolutionary past, which made eyesight a liability.
 * In Piers Anthony's Omnivore, the fungus-derived mantas use biological radar to "see" their surroundings.
 * In Lords and Ladies, elves are sensitive to magnetic fields, thus explaining their aversion to iron which distorts and "blinds" such senses.
 * Alan Dean Foster's Humanx Commonwealth setting gives us the insectoid Thranx, who have a "Faz" sense granted by their antennae. Apparently, the antennae are sensitive to air currents.
 * The Rigellians in the Lensman books use a bizarre sense that gives a worldview much like the best solid-modeling programs. They can even see things like the innermost components of shielded power reactors.
 * The Mad Scientist Travnicek in Wild Cards, after his infection due to Typhoid Croyd, develops a ring of unnatural, horn-like sensory organs around his neck.
 * In the Dragaera novels, the tendrils on the necks of dragons are sensory structures that detect other creatures' psychic energies.
 * The Lizards of Worldwar can see a few colors in the infrared spectrum.
 * The creators of the Descolada in Children of the Mind (Ender's Game series) are also implied to have this.
 * The Sphynxian Treecats of the Honor Harrington universe are telepathic and empathic, and are evidently unique in the universe in that trait.
 * On Gor, the Priest-Kings are an alien insectoid race which "talk," "hear," and mostly "see" by scent, which they perceive via their antennae.
 * In "Aftermath", a short story from The Dresden Files, the "turtlenecks" use sonar to navigate in the dark.
 * The aliens in Isaac Asimov's short story The Secret Sense are very sensitive to electric fields. The brain cells involved are present in humans but do not function; the story centers around a man who is temporarily given the ability to use this sense, but the process.
 * The extinct aliens in John Brunner's Total Eclipse were able to sense electric fields. A minor plot point is the protagonist reasoning that the aliens must have lived in constant terror of thunderstorms. He is therefore able to deduce that a bizarre bellows-like gizmo the archaeologists found must have been a device for predicting the weather.

Live Action Television

 * The Skitters on Falling Skies communicate with radio waves, which both they and the children they've Harnessed can detect.

Tabletop Games

 * In early editions of Dungeons and Dragons, many monsters had infravision (seeing in infrared), such as bugbears, dragons, dwarves, elves, gnolls, gnomes, goblins, Stout halflings, imps, orcs, quasits and trolls.
 * Much more rarely, some monsters had ultravision (seeing in ultraviolet), such as bone devils and ice devils.
 * Later editions simplified these two vision-types to Darkvision.
 * Other D&D senses include Blindsense (several forms) and Tremorsense.
 * Shadowrun: Certain Awakened creatures have thermographic (infrared) vision, including dwarves, trolls, dragons, vampires, centaurs, cerberus hounds and fomorians.
 * Native creatures of the Jorune game setting have no eyes, sensing their surroundings by an awareness of mystical energies.
 * Traveller Double Adventure The Chamax Plague/Horde: The Chamax have two sensory abilities humans don't have. First, they can detect radio waves and use triangulation to determine their point of origin. Second, they have a limited ability to detect life, which they use to search for food.

Video Games

 * The Protheans in the Mass Effect universe had the ability to read the memories of other living beings and even inanimate objects by perceiving "experience markers". This is revealed by in Mass Effect 3.
 * The Orz from Star Control appear to smell their environment. The Arilou also work hard to keep something from smelling the Humans, which imply they have a similar means of detection, mechanical or not.
 * The Orz don't actually smell as their primary sense, it's just the least-wrong translation possible for the concept of exactly how they are sensing their surroundings. Worth noting, the Orz are heavily implied to be an Eldritch Abomination. A very friendly one. Don't ask them about the Androsynth.
 * In Knights of the Old Republic II, the team bounty hunter can give a short lecture on the Bith (the bulb-headed aliens that tend to be musicians in most bars). Apparently their aural perception covers a much wider spectrum than humans', including some radio signals. However, this makes them extra vulnerable to noise and a flashbang will kill them messily.
 * The Progenitors in Sid Meiers Alpha Centauri can sense and manipulate a variety of fields, including electromagnetism. They communicate through "altering," too. While humans generate patterns of sounds, progenitors alter existing background noise and it's how they alter those sounds that determines meaning.

Webcomics

 * Homestuck plays with this. After Terezi lost her normal eyesight, she learned how to taste and smell colors to compensate. But when she contacts the human protagonists, she messes with them by claiming that all Alternians share her abilities.
 * In Arthur, King of Time and Space, fairies and Olympians can see ultraviolet.
 * In I Was Kidnapped by Lesbian Pirates from Outer Space, the main characters tend to have antennae. Word of God is that these are for some bizarre sixth sense which humans don't understand.

Western Animation

 * As Wildmutt, Ben 10 lacks eyes, yet still experiences "images" of what's around him. This perception is probably scent-based, as the images grow sharper when he takes a breath.
 * Clockwork from Ben 10 Ultimate Alien has a temporal sense that sees into the past. He can project this effect into a whole area by winding the key on his head.
 * Non-alien example: When the students from The Magic School Bus are turned into bats, they experience what echolocation is like, perceiving strobe-like flashing views of their surroundings each time they emit a sonar-cry.

Real Life

 * Some species of fish can sense electricity. Such electroreception is found in lampreys, cartilaginous fishes (sharks, rays, chimeras) and in some varieties of bony fish.
 * The platypus has this too, as does at least one species of freshwater dolphin.
 * Fish also detect motion in the water with their lateral lines.
 * Echolocation is well-known in bats and toothed cetaceans. Shrews also use this means of sensing, as do cave swiftlets and oilbirds.
 * Subverted with flying foxes and baleen whales, which don't use sonar even though most people assume all bats or whales do.
 * Thermographic "vision" is found in pit vipers, many boas and pythons, and vampire bats.
 * Magnetoreception -- the ability to sense magnetic fields -- has been found in animals ranging from bacteria to higher vertebrates, with migratory birds being the most obvious examples. Humans don't have this sense, but oddly possess a protein in the eye which could provide it.