A character is in possession of an incredible machine or device the size of a bean, which while small or seemingly inconsequential by its lonesome can do incredible things when working together with a large swarm of others like itself. In an action-oriented story they will be used as a swarm to attack someone or demolish structures, but in a more mundane situation they can be used to move objects or even a person, assemble objects or perform a myriad other tasks.
One of the greatest advantages of such as swarm is its versatility — by changing its shape and configuration, assembling and dissembling itself and shifting its attention to a single viewpoint or many to suit the needs of the moment, it can perform a much greater variety of different and specialized tasks than a single larger machine would be able to.
Related to Synchronization, Synchronized Swarming and Heart Is an Awesome Power. Compare The Worm That Walks for organic beings and The Swarm. See Nanomachines and Grey Goo for swarms of even smaller robots. Can be made an even more literal swarm if the bots are Mechanical Insects.
- Harvest, a stand that belongs to Shigechi of JoJo's Bizarre Adventure: Diamond is Unbreakable, is a collection of small android-looking bugs that Shigechi usually spreads all over town to collect things (like coins or discarded lottery tickets). However, they can form a swarm for offensive attacks or to carry him around, even to crawl up walls. This is especially evident in his video game appearances in JoJo's Bizarre Adventure: All Star Battle and JoJo's Bizarre Adventure: Eyes of Heaven.
- Lazarus: Alima, the Lazarus of the Meyers-Qasimi family, is a Cyborg who controls a swarm of tiny drones. In the X+66 side comic, she employs them to perform reconnaissance on an enemy militia, to hack into a computer system, and to wipe out a Russian Special Forces team with a word. While a close enough look at one of these drones would reveal they are shaped like tiny insects, to the human eye they generally look like a bit of cloud, fog, or even grit/sand hanging in the air.
- The Transformers (Marvel) has the scraplets — a mechanical parasite that transforms between a humanoid form and nuts and bolts. Enough of them together can transform into a giant humanoid form.
- The Transformers: More than Meets the Eye has Ammonites, a machine race that's much smaller than most Cybertronians. When Whirl meets a few in a bar who are hiding from a different Ammonite faction, he decides to help them out by killing that faction's leader. Except that he didn't really stop to ask any questions before shooting and the ones who were hiding were from the Ammonite equivalent of the Decepticons, and the one he killed was the equivalent of Optimus Prime. This led to the crew of the Lost Light discovering that A) Ammonites are Combiners and B) unlike Cybertronian Combiners there's no restrictions on who they can combine with or how many can combine together. This ultimately led to seventy billion angry Ammonites attacking Cybertron in a huge swarm during The Transformers: Dark Cybertron.
- Transmetropolitan: People can undergo Brain Uploading into "foglets", clouds of flying micromachines, each the size of a fat cell, that preserve their original consciousness. Spider Jerusalem's friend Tico is a Pro-Human Transhuman foglet who can manufacture items out of thin air, and Channon's boyfriend undergoes "downloading" into a foglet in Issue #7.
- The microbots created by protagonist Hiro Hamada in Big Hero 6 are capable of coming together in order to form structures and waldos, allowing them to perform complex tasks that would normally require many human hands with a thought projected through a Brain/Computer Interface. They are taken by the Big Bad of the film, Yokai, for his evil plans, which include forming a swarm of them to travel through town and destroy anything in his way.
- This is a plot point in The Invincible. The crew is exploring a planet where all terrestrial life seems to be missing, and which is "inhabited" mainly by unintelligent insect-sized robots. They discover the hard way that these robots combine in powerful and dangerous "clouds" which wiped out most organic life. Published in 1964, it's arguably one of the first depictions of this trope.
- Kingdom Hearts III: The biggest threat in San Fransokyo is the Darkubes, a conglomeration of Heartless that resemble a cross between Bug Blox and Hiro's microbots. The Keychain that Sora gets from this world is the Nano Gear, whose Formchange turns into a conglomerate of microbots for combo attacks taken from almost every other Formchange in the game, plus a Baymax rocket fist and a set of Kreitech portals.
- The Invincible, an adaptation of the novel mentioned above, features microbots that are more like a metallic organism than a machine. Descendents of self-repairing and -improving robots, the “Flies” that developed are around the size of a large coin and fly around in swarms. When gathered in a large cloud, they are able to produce titanic magnetic fields with which they can attack both machinery and humans. They also have a pretty black-green shimmer.
- Ofelia's Cryptobots in Insecto Nocturno are small-sized robots in the shape of starfish that she can control with her goggles. They are stolen by the titular protagonist and renamed "Crypto Sandstars".
- In Action Man (2000), after Doctor X takes over Brandon Cain's body, Brandon's mind accidentally goes into a nanotechnological Trillabug, which takes control of all other Trillabugs, forming a monstrous version of Brandon.
- In the episode "The Love Bug" of Aladdin: The Series, Greek Evil Genius Mechanicles has invented a swarm of mechanical termites to destroy entire forests. The ultimate thing these termites can do is combining into a Mini-Mecha around Mechanicles.
- In the Futurama episode "Benderama", Bender uses the Professor's new matter replicator to make small copies of himself, who then make smaller copies of themselves until the world is beset by millions of microscopic Benders who are small enough to manipulate individual atoms and turn all water on Earth into alcohol (which powers them). For the climax, they form together into one giant Bender to fight an alien giant.
- The Ultimate Spider-Man (2012) version of the supervillain Swarm is made of nanomachines instead of bees like his comic book version.
- Played for Laughs with The Cone Army, a collection of 37 identical small robots attached to street cones. Its intended use was for combat against other robots on BattleBots, but it was turned down during auditions.
- Although it doesn't exist yet, "utility fog" would be pretty much this: a swarm of machines the size of dust grains, with the ability to assemble into any structure we might need.