So, you know how we call the Tracking Device a bug, since we all tend to speak American and are therefore too lazy to say more than one syllable?
This is what happens when a clever writer realizes that hey, maybe it actually can be a bug! A robot bug, with cameras and laser beams! Awesome! You can even replace the Sci-Fi with Magic, if need be.
All of this on top of the fact that bugs themselves are rather unobtrusive, and people don't usually shriek in horror when there's just a random bug hanging around, minding its own business. And whereas people might begin to get suspicious if the telephone sprouted helicopter blades and followed them into the next room, an insect flitting from wall to wall is entirely uninteresting. As a result, they tend to be both cool and practical. It's hardly surprising that this trope appears in Science Fiction, Fantasy, and everything in-between.
If someone does — usually out of sheer force of habit, rather than suspicion — swat the bug in question, expect anyone in headphones on the other end to get a painful dose of screeching feedback.
This trope isn't just restricted to fiction, either—it turns out that actual beetles can be manipulated in such a way that they work as great surveillance, although full applications of this are still in the works. These studies also discredit one common appearance of this trope—robotic bugs. It turns out that they're Cool, but Impractical, since making them work pretty much requires that scientists make them as much like actual beetles as possible.
All of which gives a whole new meaning to "Fly on the Wall".
Subtrope to Animal Espionage.
- In Naruto, Shino Aburame gives orders to the bugs that live in his body, and can have them perform surveillance (they communicate with him by flying in pattern to form words) or track (he puts a female bug on his target and then has male bugs find it by scent).
- There's a bard in Scrapped Princess who learned to control swarms of robotic bugs running on Lost Technology and uses them, among other things, for spying on people.
- There is one in Yu-Gi-Oh!, property of bug-themed Weevil Underwood.
- Baikinman's team uses a spider-shaped electronic bug (ehh... right) in an Soreike! Anpanman movie (it was either Ruby no negai or Yumeneko no kuni no Nyanii). Apparently Baikinman got over his hatred of spiders when he transformed into one in Baikinman no Gyakushuu.
- We have these to thank for the entire Android / Cell Saga in Dragon Ball Z. After Goku defeated the Red Ribbon army, Doctor Gero had bee-sized robot bugs running surveillance on all Goku's battles except for those on Namek. This allowed Gero to a) calculate the growth of Goku's abilities so he knew how strong to make the androids, and b) collect DNA samples from human and alien fighters to make Cell.
- Tiny robot bugs with a large field of vision show up in both Arachnid and its spinoff Caterpillar to spy on the ongoing battle royales. This is but a sample of the setting's fixation on bugs.
- Spider-Man's spider-tracers. Whose signal he picks up with his spider-sense, in fact.
- In Astro City, although Jack-In-The-Box trains a replacement due to familial obligations, he follows the new Jack with a remote-controlled flying spy camera and provides him with real-time situational updates.
- In The Mighty Thor #357-8, the villains' secret base has an insect infestation that's actually a swarm of Literal Surveillance Bugs created by their own Gadgeteer Genius, who is working with them unwillingly and wants to know what they say when he's not around.
- The Simpsons: An early issue has the FBI keeping watch on Mr. Burns via one of these, until Smithers notices it.
Mr. Burns: Oh, worried about bugs, are we? I eat bugs for breakfast. Let them eat static!
FBI Agent: It... it's still working. I can hear chewing and swallowing.
- In Game Theory, Megane primarily uses her summoned insects for discrete surveillance.
- Starlight Over Detrot has the Ladybugs — magically constructed out of parasprites and a host of other things, they can telepathically share information across their Hive Mind, and to anyone wearing one of the bugs.
- The New Adventures of Invader Zim features Zim spying on Dib with one of these in the first chapter.
- The bird in The Incredibles.
- R.A.L.P.H. (imaged above) the Robotic Arachnid Lithium Photo Helper from Spy Kids 2: Island of Lost Dreams.
- One pops up in the 2008 remake of Get Smart, where Bruce and Lloyd capture a small robotic fly.
- The Spyders in Minority Report are four-legged robots which invade people's homes to do a retina scan for identification. Those who don't open willingly will be shocked until they comply.
- A cockroach (with a really obvious set of surveillance gear strapped on its back) in The Fifth Element. Leading to a hilarious moment when the President squashes it (thinking it is just a bug) and the man listening receives the noise of the strike many times louder plus feedback.
- The Matrix has the tracking device Smith places in Neo's body. When it's about to be surgically removed from Neo's body, Trinity explains to him, "We think you're bugged."
- Mooch the Fly from G-Force (2009).
- G.I. Joe: Retaliation: Firefly's robo-fireflies, which also double as anti-personnel explosives.
- Ant-Man: Unsurprisingly, Hank Pym uses ants carrying micro-cameras to spy on Scott (before recruiting him as Ant-Man) and to follow him on missions (afterward).
- The Animorphs would frequently morph bugs for surveillance purposes.
- Rita Skeeter in the Harry Potter books can actually transform into a bug, and uses said ability for exactly this purpose. In this instance, it's a learned skill, albeit one that is supposedly regulated by wizarding law. Hermione was set on the path to discover this fact by Harry talking about "bug" in the usual surveillance sense.
- Deception Point by Dan Brown has the spy bugs used by Delta Force.
- This is part of the Palantir Ploy in Abarat—the Midnightian Royal Family has robot spy-bugs and spy-birds and spy-who-knows-what all over the place. Candy actually beats one up once, to prevent it from hurting the child of the kind lady who gave her shelter.
- One features in the opening chapter of Roger Zelazny's Lord of Light
- A Danny Dunn book (science fiction for '60s youngsters) has this for a plot — the eccentric scientist invents a dragonfly that can be remote-controlled by virtual reality, and three kids get hold of it and use it for their own purposes (mostly tormenting the local bully, but also spying on crooks).
- The clockwork "spy fly" in His Dark Materials.
- In The Neutronium Alchemist by Peter F. Hamilton, an intelligence agency is using biotech spiders to spy on a radical group. Realising what's happening the group arranges for gangs of local kids to squash every spider in sight as a game.
- In Pandora's Star, also by Peter F. Hamilton, Paula Myo and her team use modified insects to spy past privacy shields that scramble any electronic attempts at spying.
- In the Liaden Universe novel Fledgling, Win Ton catches an insect-like device spying on the Delgado party (though it is referred to as a "spying device" as the parties discussing it apparently do not use the colloquialism "bug").
- In the first Star Trek: Titan book, the Romulan Tal Shiar (their state intelligence agency) use tiny crawling robotic bugs to eavesdrop on a closed meeting of Romulan and Federation dignitaries. The devices are discovered only afterwards, but do prove useful in a later mission (in the next book of the series).
- The Artemis Fowl series has ARClights, genetically-engineered dragonflies carrying biotech cameras, created by Foaly.
- Rune uses the magical variety in the Relativity story "Rune Returns... Again".
- Whateley Universe:
- Not only bug-shaped but also with a cloaking field in "Ayla and the Tests".
- Cyber-Swarm specializes in them.
- In The Stormlight Archive, the Dysian Aimans are Hive Minds controlling hundreds or thousands of small arthropods they call hordelings (small arthropods in general are usually called 'cremlings in universe). They can form them into a surprisingly convincing human shape but they can also use some of them as remote observation agents. An unknown number of Dysians have taken an interest in the series main characters and apparently are the in-universe authors of the back cover blurbs for the novels. The exact nature of their interest is currently unknown. Since this was revealed fans have made a bit of a game of trying to spot the Dysian spies. One is confirmed, the cremling that appears in the epilogue of Words of Radiance.
- Consider Phlebas. Horza swats away an insect that has somehow made its way onto the spaceship. The insect lands on his hand for a moment, and Horza only realises later (when agents from Special Circumstances try to detain him) that it was a tiny surveillance drone confirming his identity by sampling his DNA.
- Get Smart. In "Double Agent", there was a fly "bug" in development, but Max (of course) thought it was a real fly and swatted it.
- In The X-Files episode "War Of The Coprophages", Mulder stumbles upon a swarm of methane-powered robotic alien space probes disguised as roaches who have been conducting research on a small town in New England. Because they have a tendency to swarm over the recently-dead in order to collect samples, the townsfolk erroneously believe them to be responsible for the deaths and mass hysteria over killer cockroaches ensues.
- Flying robotic bugs were used by Mega-Corp Vex-Cor in Charlie Jade.
- Skylar in Alphas makes these.
- In one episode of The Dresden Files TV series Harry used a spell to make some bees into these: it involved having them sting his ear so he could hear what they heard.
- Star Trek: Voyager. In "Lifeline" the EMH goes to visit his creator, hologram expert Dr Zimmerman, and finds himself being bothered by a buzzing fly (as per usual for this trope, he ends up swatting it despite being a hologram himself).
Barclay: Oh that's Roy.
EMH: Don't tell me — another hologram?
Barclay: It was developed for Starfleet Intelligence; an experiment in micro-surveillance.
- Veronica Mars: Veronica once planted a bug inside a paperweight of a beetle.
- Altered Carbon. A surveillance drone that looks like a metal fly is used by the Ghostwalker to record Takeshi Kovacs having sex with Miriam Bancroft, the wife of his wealthy and powerful employer. The next day a couple of them are shown to Takeshi by Poe (the avatar of the hotel's Artificial Intelligence) pinned like butterflies. Unfortunately Poe says that he detected them too late to stop them transmitting what they saw.
- The Scuttle Buddy from The Adventure Zone: Balance.
- The Dark Crystal has surveillance bats.
- Champions adventure Deathstroke (1983). The villain group The Destroyers use spy devices disguised as insects to guard their hidden base.
- The Loyalty Roaches from Feng Shui's 2056 juncture are how the Buro keeps its eye on its citizens. The watered-down "environment-safe" insecticides common in 2056 don't do dick to them, but the ones in the contemporary juncture, which are obviously banned by the Buro, do a bang-up job on them.
- In one mission of Sly 2: Band of Thieves, the team rigs a beetle into a survailance bug, with Lampshade Hanging.
- The Humongous Entertainment SPY Fox games have Walter Wireless the Tracking Bug, a Walter-Cronkite-impersonating bug whom Spy Fox drops into the bad spy's purse, or whatever. He gives news reports on the villain's status while riding with them.
- In the Sam & Max games by Telltale, there was a literal talking bug with a Drill Sergeant Nasty voice. Apparently he was in Vietnam too.
- Call of Duty: Black Ops II has you deploy a spider-like bug named Ziggy during the Colossus mission, equipped with a camera, microphone, wall-climbing capabilities, hacking equipment and a short ranged stun device.
- The Beetle serves this function in The Legend of Zelda: Skyward Sword. Not only does it allow you to retrieve small items and press unreachable switches, an upgrade also allows it to carry larger objects (pots, bombs, etc.), and subsequent upgrades provide it a longer range and the ability to accelerate.
- Too Human: a Cyber Punk adaptation of Norse Mythology, turns Huginn and Muninn into robotic birds with zoom-lens eyes.
- James Bond's Q-Spiders in Everything or Nothing. They're variously equipped with explosives, tranq-darts, invisibility cloaks, and missiles (used only once).
- Ratchet & Clank: Going Commando has the Spider-Bot, a remote controlled drone that Ratchet can use to survey areas outside of his line of sight, flip switches out of his reach, or blow up unsuspecting enemies.
- Hinted at in The Order of the Stick #770 when a prisoner in the Empire of Blood says about having been captured after escaping:
Ian: I don't know what tricks they're using to find me yet... my current theory is that they've bugged my bugs.
- Part of LBB's function in Agents of the Realm. LBB stands for Ladybug Bot and Jade uses it to search for both Agents and bleeds.
- Wilde Life has spiders act as watchers, heralds, and if need be defenders, in the name of the White Faced Bear.
- Mechanicalles made some of these in Aladdin: The Series.
- The Monarch uses butterflies like this in The Venture Bros., although you can't help but wonder why no one notices that butterflies are, in fact, The Monarch's whole supervillain theme. It helps, of course, that as far as Dr. Venture is concerned The Monarch is an Unknown Rival.
- Vlad Plasmius uses mechanical bugs that resemble him to spy on the Fentons in Danny Phantom.
- The Predacons in Beast Wars sometimes use these.
- In Wakfu, Nox uses the "Noxines" clockwork bugs for both surveillance and to gather wakfu from all over the world.
- When spying on Global Justice and Kim Possible, Gemini uses robotic Fly-On-The-Wall cameras, which often lose signal because people keep swatting and breaking them. When interrogating his underlings about the signal loss, they mention that when people see things that look like flies, they swat. Gemini never takes this advice reasonably.
- One of the later DIC-season episodes of G.I. Joe had many high-ranking Joes under suspect for being The Mole since Cobra always seemed to have strategic intel that was only discussed in very confidential meetings. After investigation, none of the Joes present was found to be a spy, but General Hawk always brought his favorite cookies to the meetings and Cobra programmed a collection of robotic cockroaches to seek these cookies out.
- In Teenage Mutant Ninja Turtles (2012), Donatello has been known to make "spy roaches" by outfitting ordinary cockroaches with cameras and somehow controlling their actions via remote control. Raphael, who hates cockroaches, doesn't approve, especially after one of them mutates and holds a grudge against one of Raphael's freak-outs.
- Yogi's Treasure Hunt: One episode features Dick Dastardly using one to find out where the good guys will go to search for the treasure of the week. Someone swats it without realizing what it was but Dick is satisfied because it at least lasted long enough to fulfill its purpose.
- Inch High, Private Eye. In "Super Flea" the invention of this trope threatens to put the miniscule private detective out of a job.
- Special Agent OSO has a tiny ladybug-like robot called Shutterbug.
- Dexter's Laboratory episode Repairanoid, Dexter sends out a fly bot to find out why his lights are flickering. The electrician sees the fly but assumed it to be a ordinary fly and squashes it.
- For those interested in how this trope is being applied in Real Life, some YouTube links for your perusal.
- Alleged first example of some kind of this trope would be CIA's project to implant a microphone and a radio in a cat (fun fact: the antenna was going through the tail). Thus created spy-cat would have been given to persons of interest as a inconspicuous gift. Then, during field tests, first ever spy-cat was run over by a car in minutes since its release, and the project was scrapped.
- The Insectothopter, a 1970's bug disguised as a dragonfly.