The setting is a homeworld exoplanet of an alien species, abandonded (save a hibernation cycle-style subterrainian research settlement) for conservation after a 10 000+ year prior climate collapse. this setting is part of most of my questions on this site. The story takes place roughly 60-70 years into a collapsing human settlement, and shortly after the aliens (for the purpose of clarity, I'm aware the humans are the aliens in this situation) wake up and announce themselves, a war breaks out.

The humans are mostly scatered and starved of resources, mostly due to past civilization on the planet using non-renuables, with a population of probably a little over 100 million over a small area, wrapped around a large river delta. The capital boasts a large military force, with basic and expensive hover tech and advanced projectile based weaponry. They figured out interplanetary space travel, but they got to the new planet via a natural, Sol-adjacent wormhole, so not technically interstellar tech level.

The native race has a very small population of mostly scientists, low infrastructure, and advanced tech (including energy-efficient low-altitude flight and advanced genetic engineering). Almost all their tech is made of bio-organic machines, including vehicles and service machines/animals. This biotech seemlessly incorporates metal alloys and other materials in a way that allows machines to be grown, bred and even consumed by other machines to recycle material.

Nano storm weapon:

Long preface, I know, but I introduce the tech because the setting makes me think the best idea the native city could use to defend is to make a lot of simple, small machines, able to be controlled by a small team of operators. These nano machines would work as you have probably seen in other scifi, a semi-hive mind storm of low-cognition units that can be allocated large/complex tasks.

Each machine would be able to break down and alter both organic and in-organic stuctures. With a quick enough strike, small team of nano-storms could disarm and dismantle a decent armada of tanks and infantry in a few hours with miniscule sentient loss of life, provided the operators only dismantle equipment and not soldiers.

This kind of tech is well within the range of my native race, but this is a story, and I can't just have the human threat be annihilated so quickly. How would a human army defend against such a weapon? What kind of counter-weapon might near-future tech provide?

Keep in mind he AI of these machines is organic, neuron-based, so Independence Day computer virus isn't gonna cut it. Also, i'm aware this may be too vague, but since it's been a bit of a hole in my writing for a while I felt the need to ask.

  • $\begingroup$ @user535733 I’d assume the functional parts of the swarm would recognise the deviant and deconstruct it, though a hive cancer is an inspiring idea - worker bees have a rare behaviour where one spontaneously becomes fertile and challenges the queen. $\endgroup$
    – XenoDwarf
    Sep 22, 2020 at 12:12
  • $\begingroup$ Humans have disgusting plastic armor which clogs the Nano™ Machines. Or alternatively, finding out that the Nano$^{\text{®}}$ Machines can indeed eat the indestructible plastic which is choking Earth in a sea of refuse, the humans ofer to enter into a Totally Benevolent Free Trade Agreement$^{\text{©}}$, offering Free Fay Sbook and Free Ute Ube in exchange for some Nano℠ Machines to take home. The hapless defenders accept, and while the operators are distracted by pictures of food and cat videos, the invaders strip starkers and fashion catapults out of local wood which is not attacked. $\endgroup$
    – AlexP
    Sep 22, 2020 at 16:50

4 Answers 4


Misinformation, taking over or otherwise interference

The machines are controlled by a powerful AI. However, the machines are low cognitive machines that work together. Their low cognition and communication to each other/the AI makes them more vulnerable to misinformation or taking over commands. Finally, they are allocated to certain tasks. Without constant supervision, you might be able to protect yourself by excluding yourself from the task.

To take over the machines, you must check the way they communicate. The AI is probably communicating to a few command nano machines, because talking to them all at once seems inefficient. The command machines can then relay this information to the swarm they control. Likely several command machines are in place per swarm segment as redundancy. If they use radio for example to communicate, you can send command signals over these waves to turn them off or against their creators. You can also just throw noise over these channels to prevent new commands to be received. Finally, you might infect the simple minded machines with a virus to disregard further orders. Despite the AI being immune, the simple minded machines might not be.

The machines must also communicate to each other, besides the command machines. Here you can also introduce commands to take over or misdirect.

You can also check their task. There are ways they identify what they need to destroy. The initial command might be complex and fool proof, but in the end small simple machines need to have simple commands to identify what they should or shouldn't destroy. If they are to identify certain enzymes, DNA or simply a certain plastic for example that many of the human equipment have, it can be removed or replaced. No identification, no horrible death or equipment destroyed. You can also create a diversion by making a huge pile of the thing they identify for destruction. The swarm probably identifies it as an important hot spot, and sends a lot of machines there to destroy everything.

Finally, the machines are organic, neuron based machines. This makes them highly vulnerable to (nerve) poisons. Throw in some nerve gas or general poisons around an area. Not foolproof, but certainly a good deterrent against large swarms. You can also poison the huge piles of whatever they identify. Or go the real distance. Engineer a virus specifically for these swarms. The AI will devise new swarms or improve the old to be immune. Then a new virus will target the next weakness. Eventually you'll be able to use older viruses, as you need to give up some immunity at a certain moment, making it a circle or infection and immunity.

These things will certainly slow them down, if not outright stop them.



Your nano machines trundle out and hug opposing forces and machines. They just glom on and stay. They do not otherwise damage the thing. They are pretty durable. If you peel one off and it has any life left in it, it will hug something else. Hugging does not damage things. A nano machine hugging a tank tread might jam it up. If it hugs a soldier it will slow the soldier down and might make it tough for him to get at his equipment. Soldiers might have to ditch packs and coats that have these nanos hugging them. Each nano unit weighs about 500 grams.

They really are mostly annoying, the hugbots, and also kind of pathetic. They are semi sentient and can talk a little bit which makes them more annoying. They say things like "go away and leave us alone", "we don't have any good stuff", "we are hungry too", "you smell nice" and so on.

The humans get the idea that maybe it is not worth attacking the aliens if the hugbots are the best they can do. Maybe the hugbots are right and the aliens really don't have much.

  • $\begingroup$ Brilliant. My hugbots could exude little red heart-shaped adhesive blobs $\endgroup$
    – user535733
    Sep 22, 2020 at 15:50
  • $\begingroup$ How can something of half a kilo be called 'nano'? $\endgroup$
    – Trioxidane
    Sep 22, 2020 at 15:50
  • $\begingroup$ @Trioxidane - it is pathetic, poor man's nano. $\endgroup$
    – Willk
    Sep 22, 2020 at 19:57
  • 1
    $\begingroup$ Or they are 500000000 kilo hug bots scaled down. $\endgroup$
    – Trioxidane
    Sep 22, 2020 at 20:40

It depends how capable the nanobots are without further orders from the operators?

If this battle was taking part in space over larger distances you could cut off the nanobots communication with their operators by dividing the swarm, taking parts of it out of the range of the operators communication, then create to much chaos for the swarm to understand with its basic functions or lead it to a trap.

Since this battle is fought on a planet and underground tunnels are available the same process can be done, splitting the swarm taking them to isolated locations possibly with materials blocking further updates and orders then you have the opportunity to lead the smaller, hopefully less capable groups of nanobots to hidden traps.



Mutually Assured Destruction. The aliens have the capability to wipe out the humans but the humans have brought nukes with them. Any direct attack, the humans would turn the planet into a radioactive parking lot.

It's what stops the countries of Earth from destroying each other.

The aliens need a more subtle method of attack.

  • $\begingroup$ Assuming the aliens don't dismantle the nukes (and all the other weapons) in a preemptive strike $\endgroup$
    – Gianluca
    Sep 23, 2020 at 15:12
  • $\begingroup$ But that assumes they can and not be detected because being detected is reason to use them. If the aliens can dismantle the humans weapons secretly then what defense could we possibly have? Makes the question redundant. $\endgroup$
    – Thorne
    Sep 23, 2020 at 17:12
  • $\begingroup$ MAD is useless: once humans notice the attack, their nukes are (at least) disabled. Or, worst, make to detonate where they are. $\endgroup$
    – Gianluca
    Sep 24, 2020 at 10:08
  • $\begingroup$ Yeah na. Considered they came from Earth, in all likelihood have orbital platforms and the possibility of new ones being sent. They can't ever be sure of stopping all the nukes. All else fails, they could take the disarmed bombs to pieces and build some dirty bombs to irradiate the surface of the planet. $\endgroup$
    – Thorne
    Sep 24, 2020 at 23:13
  • $\begingroup$ Fine. But all this require times, and if your side of MAD is removed, aliens can do whatever they want. What about wrecking every piece of your infrastructure, even if only damaging to various level everything, a building collapsed here, communications stop there... Moreover, are we sure that the aliens have not a tolerance to radioactivity way higher than humans so they just don't care ? $\endgroup$
    – Gianluca
    Sep 26, 2020 at 17:49

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