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 Nano Machines and Grey Goo for swarms of even smaller robots.
- Harvest, a stand that belongs to Shigechi of Jo Jos 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.
- 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 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 Transformers: Dark Cybertron.
- The Transformers had 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 microbots created by protagonist Hiro Hamada in Big Hero 6. These microsized robots are capable of coming together in order to take many different forms, allowing them to perform complex tasks that would normally require many human hands with a thought projected through a transceiver. 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 Stanisław Lem's 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.
- Supergirl (2015): In the Season Two episode "Ace Reporter", the Villain of the Week gains control of nanobots that are originally intended for medical use and give an instant Healing Factor. However, the nanobots can also do the opposite and destroy a normal human body in an instant. The villain can also use them for mind-control and, in big enough numbers, can even asphyxiate a Kryptonian.
- Played for laughs with the nanites in Mystery Science Theater 3000, who regularly go on strike or rebel since they hate their jobs.
- 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.
- The Ultimate Spider-Man version of the supervillain Swarm is made of nanomachines instead of bees like his comic book version.
- 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.
- In The Powerpuff Girls episode "Nano of the North", the titular girls have to fight off a swarm of carbon-eating nanobots that are attacking the town.
- The Young Justice episode "Infiltrator" features the team battling to neutralize "the fog", composed of millions of nanobots.
- 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.