Would a mage with the ability to control roughly 3000 insects at once be able to kill roughly a 1000 knights charging at him with the intention to kill him? If so, which insects would be suited to do so? Would be awesome to get 3 or more at once, for the sake of diversity.

I'm asking for insects, which really exist in reallife, so no enhanced fantasy novel stuff. And it doesn't matter, if your chosen insects don't naturally life in the same area.

(Knights don't own magic or have any stuff that didn't exists in the medieval pre-gunpowder ages. They also only wield sword and shield, so no ranged weapons.)

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    $\begingroup$ You are asking about a story set in a world, not about building the world. $\endgroup$
    – sphennings
    Aug 2 '17 at 19:38
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    $\begingroup$ Must the knights be killed (as in the title)? Or can they simply be tortured and harassed (as in the last paragraph)? $\endgroup$
    – Pyrotrain
    Aug 2 '17 at 19:40
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    $\begingroup$ This is really broad. You could always just drown them in insects if you had enough. Or if you had time, riddle them with disease. You even gave two examples in your question. You might consider limiting your mages powers in some way, he sounds a bit overpowered. $\endgroup$
    – Wolfgang
    Aug 2 '17 at 20:02
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    $\begingroup$ Nitpick: spiders aren't classified as insects. It's up to you whether you want to stick to that modern scientific classification, extend your character's powers to include (say) all arthropods, or hand-wave it as "anything they would consider to be 'insects' in their medieval classification system." $\endgroup$
    – DLosc
    Aug 2 '17 at 21:47

I will first comment that you've limited yourself rather severely. In a locust swarm, a "large swarm" consists of billions of individuals, with eighty million locusts per square kilometre not being unusual. Controlling 3000 of those will not do you any good, either to deploy such a swarm or to defend against such a swarm.

But if we're limited to 3000 critters, we want maximum bang for our buck. So...

If you're limited to actual insects and the knights are charging

  • Japanese Giant Hornet - These things are nightmares IRL. They may not carry the most deadly venom, but they've got a lot of it, and it attacks the nervous system. Assuming you have a generous resupply stock as the knights manage to kill some of your troops (they're big enough for even a slow-moving knight to swat, after all), this is your air force, and it should kill a fair number of the oncoming knights.
  • The Bullet Ant - These guys aren't here for the kill, but to incapacitate. They have the most painful sting of any insect - akin to being hit by a bullet, hence the name. It would be hard to imagine even the most determined knight shrugging off more than a couple bites from one of these, and that would give your killer hornets an opportunity.
  • The Tarantula Hawk Wasp - These friendly guys come in #2 on the "most painful stings" list, after the bullet ant, but have the added bonus of wings, for mobility! The bullet ant's sting is also longer-lasting, while this guy's sting is described as "shutting down all ability to do anything for five minutes but scream". Players of Fallout: New Vegas will recognise this as the inspiration for the cazadores, arguably the worst things one encounters in the game, and for good reason.

So, your knights start across the battlefield towards your encampment, only to collapse screaming as it feels like they've been shot in their feet. Brightly coloured wasps then land on their armour, worm their way inside, and suddenly the knights are screaming louder and convulsing as the tarantula hawk's venom takes effect. And then a strike team of thirty giant hornets moves from knight to knight, replenished from your giant (and terrifying) terrarium as they run out of venom, dosing each knight with enough to cause death by anaphylaxis or renal failure.

What if the knights aren't charging?

Let's say your advance scouting dragonflies tell you about the knights before they actually reach the battlefield? Then what you want is...

  • The Tsetse Fly - The insect is synonymous with sleeping sickness, and there's a reason for that. You might not get all of them, but the vast majority of your knightly opponents would sicken, fall asleep, and never wake up. Sends a powerful message, that.

What if we allow arachnids to the mix?

Here, things can get even more interesting, as you can introduce...

  • The Brown Recluse - This is the kind of spider nightmares are made of, mostly because of the activity of its venom. The black widow gets more press, but its bites are actually fairly seldom lethal, and you want to kill these knights. Ten brown recluses, small enough to scurry through chinks in armour, make the odds very good that their target, lacking sufficient medical attention, will die. And even if they don't, necrotic lesions near the bites where the knight's flesh rots away... will probably sufficiently incapacitate them (especially if the recluses are directed to bite important or sensitive areas) to make sure they are permanently taken off the field.

Still, though, the real power of insects is numbers, and 3000 seems an arbitrarily low limit for their use. Even with that limit, though, the nastiest insects that Earth has to offer will probably turn the trick for you.

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    $\begingroup$ As an addendum, if you were fighting off a swam of locusts that was destroying a farmer's fields (assume half a square kilometre in total), and it only took a second to implant the command in a locust to find the nearest body of water and drown itself, it would still take four hours of continuous work to clear one field - assuming no adjacent locusts moved in when the others left. $\endgroup$
    – jdunlop
    Aug 2 '17 at 20:49
  • $\begingroup$ If allowing arachnids as well, consider also the Sydney funnel web spider. Median time to onset of envenomation is 28 minutes, and deaths have been recorded. Plus, the bites are very painful. $\endgroup$
    – Aliden
    Aug 2 '17 at 22:36
  1. Open with mosquitoes. Mosquitoes with chikungunya.

From https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/chikungunya

Approximately 3%–28% of people infected with chikungunya virus will remain asymptomatic. For people who develop symptomatic illness, the incubation period is typically 3–7 days (range, 1–12 days). Disease is most often characterized by sudden onset of high fever (temperature typically >102°F [39°C]) and joint pains. Other symptoms may include headache, myalgia, arthritis, conjunctivitis, nausea, vomiting, or a maculopapular rash. Fevers typically last from several days up to 1 week; the fever can be biphasic. Joint symptoms are often severe and can be debilitating. They usually involve multiple joints, typically bilateral and symmetric. They occur most commonly in hands and feet, but they can affect more proximal joints. Rash usually occurs after onset of fever. It typically involves the trunk and extremities but can also include the palms, soles, and face.

Chikungunya is good for its fast knockdown. And you feel miserable but rarely die. If you have not got chikungunya, dengue or yellow fever will do. With any of them you slow down and that is good because next up are the lice, and lice are slow.

2. You send lice. Lice with typhus.

from http://1632.org/1632tech/faqs/typhus.html

The disease has an incubation period of 5 to 14 days. It first appears with rapid onset as fever and severe headache. Extreme fatigue, nausea, vomiting, and chills frequently appear. After about 4 days, a rash appears. Toxemia appears, circulation becomes sluggish, and gangrene may appear in the extremities and genitals. The victim becomes stupor us. The crisis occurs after 9 to 12 days, and about 1/3 of those infected slip into a coma and die, usually of cardiac failure, frequently with pneumonia as a complication. After 14 days, the fever may disappear and recovery follows.

Lice love military camps and 1000 knights means at least 3-4 times that total number in the camp. Perfect.

  1. You saw it coming. You close with fleas. Of course this is fleas which carry Yersinia Pestis; plague. Plague should do for the knights as well as the countries they hail from. With an incubation period of 1-3 days you could start and end with the fleas, but you wanted 3 different bugs. If it looks like the knights are going to find you before they get sick from #1 or #2, start with the fleas.

It might not be easy to find lice with typhus or mosquitoes with chikunguya. Plague, however, is endemic among rodents and you should be able to turn up some likely fleas. It is possible you might need robber flies to carry them there but they will be happy to help.


If your intention is to kill them off quickly, then I would think something like a colony of hornets could be a powerful ally.

hornets, like bees, communicate using pheromones. By simply controlling one hornet you can create a breadcrumb trail of pheromones that will lead the defenders of the nest to the knights. The benefit of the this approach is you can potentially get several different hives together, overcoming the control limit you have. The downside is that different hives have different pheromones and the hornets can potentially start fighting amongst each other. Wasps stings are deadly to people with allergies, but they also cause swelling that can lead to asphyxiation if enough of them are delivered to the face or neck.

However, you could also go the marathon route and have locusts eat the crops and kill the livestock. Or you can send a cloud of mosquitoes or ticks and spread disease amongst the people. I don't think 1000 knights will be too eager to hunt you down if they're hungry or suffering from malaria/lyme disease.

  • $\begingroup$ +1 for locusts eating the crops and killing the livestock $\endgroup$ Aug 2 '17 at 20:36
  • $\begingroup$ @marcellothearcane - except that 3000 locusts does not a crop eat. $\endgroup$
    – jdunlop
    Aug 2 '17 at 20:45
  • $\begingroup$ @jdunlop I see, not that into locusts myself, so I wouldn't know! It's only 3000 at a time, actually all of them are available: 'And you can control insects. All of them. If they exist (in our world), you have them at your disposal. And you can control roughly 3000 of them at once.' $\endgroup$ Aug 2 '17 at 20:48
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    $\begingroup$ @marcello - sure, but as in my answer, an average locust swarm is billions of insects. So even if you can focus hard enough to switch which 3000 you control several times a second, directing the swarm would be like trying to reroute a river with a toy bucket. $\endgroup$
    – jdunlop
    Aug 2 '17 at 20:52
  • $\begingroup$ @jdunlop okay, that's more than I thought. couldn't you try to put as many as possible in the vicinity, and hope they'll go to the food? Only 3 days of constant magic as you say... :P $\endgroup$ Aug 2 '17 at 20:56

Assassin bugs to start with. Make sure they carry the Chagas parasite. They are small enough to get in through any medieval armor. Have them target the eyes.

The most deadly animal in the World, the Mosquito loaded with Malaria and Dengue Fever. Again, get in to the helmet, near the eyes. That is your second wave.

Your Anti Cavalry Send the scorpions to take on the horses. Direct them to places that will make the horse react violently to the sting. With luck the horse will throw the rider. If not, have the scorpion sting in a way to get the horse to kick the humans on the ground. Make sure the critter is seen.

The point of going for the eyes and face and being seen is to reinforce that this is not random, that a bug is doing the deed, and that you are not to be triffled with.

Mosquitoes especially can keep the infection rate up with multiple bites, and each infected guy serves as a source for the other mosquitos to keep transmitting the disease.

Keep it going with wasps, hornets, ants, and centipedes. Go in waves and go for the head. You get a high mortality rate for the diseases, pretty good horse related damage, and occasional anaphylaxis.

Hide as deep in the forest as you can and have your little helpers just attack in small wave after small wave. Maybe let the knights see hints that you are there, but never let them see you directly. Hey, get some cockroaches together to pile up in a humanoid shape then scatter so another wave of Assassin bugs attacks

100% mortality is probably not going to happen, but any Survivors are going to get really scared,especially when you chase them out with spiders

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    $\begingroup$ Minor quibble - scorpions and centipedes aren't insects. $\endgroup$
    – Mike G
    Aug 2 '17 at 21:19

Can you slightly bypass the problem?

... and can you control insects far away?

Send a letter to the king warning him that if a single knight shows up within 20 leagues of your forest, his closest adviser will die. When the first knight shows up, have a swarm of 3,000 creepy crawlies descend upon the adviser - in the middle of court, where it's very, very visible. Make sure the king can see it.

To enhance the creepiness, use multiple kinds of insects: say, 500 each of six kinds: a few stinging insects, a few biting insects... at least one that's there for the visual effect, at least one that is at least somewhat poisonous or likely to cause allergic reactions. 3,000 fanatical insects against a single unarmored man is probably a "sure bet"; watching 3,000 insects single-mindedly target and kill a person is going to be disconcerting. (Note that the specific kind of insect is not so important: just make sure that you have some for the visual effect, and enough for a physical reaction - even if it's just overloading the system with a weak poison.)

Then send a second letter to the king: the next time you see a knight, the king himself dies...


Insect control can be terrifying.

First he should choose the entire forest as his battlefield. He should never come to grips with them, ever. The first order of business is to keep them chasing the wrong thing. Send clouds of insects to look like a dark figure off in the trees across the glade or over among those trees. The knights will be chasing phantoms endlessly or think that he is everywhere watching them, which he is...

Second he should hit them when they are camped. Send ants into all of their rations to starve them. Have the insects drive off the animals so there is nothing to hunt.

Third he sends 3000 ticks to drink two people dead. He draws them into ponds chasing that phantom then has leeches swarm a few of them and drink them into madness. Maybe he sends the ticks to drive a massive bear to madness and draw the knights into it. So being bled to death, starved and attacked by mad beasts for a week non stop will drive them to call it quits. If they stick it out then he gets rough.

Forth, he gets the local most poisonous insect, brown recluse is the most likely, and have them attack random knights at random with as many stings as possible. With a dozen knights a night dying to wasting poisons or waking mutilated by ticks, leeches etc by the end of a week they will have lost 80 or 90 knights and have many others snapping under the strain.

Fifth... get his mosquito to drink rabies infected blood and give as many people a shot of it as possible. May require the leeches or ticks but the idea is to infect enough knights so that they start attacking the rest of the knights. The mage could do something to the mosquitoes so that they can carry it.

I think with all of the ways he can directly and indirectly attack the force that he wouldn't be in any danger unless they try to burn down the entire forest.


Why not control 3000 Japanese Giant Hornets from 3000 different nests? It sounds a bit far-fetched, but each hornet can sting a knight, release a pheromone to attract other hornets from its hive, and cause absolute mayhem. It will overcome the bugs-controlled limit hundreds of times over. Even if there's only a 50% success rate, half the knights will get stung twice anyways!

I guess you have to have 3 kinds of insects, so maybe 3000 Japanese Giant Hornets won't work. However, you could use similar strategies with other insect species (e.g. bullet ant scouts) and attack with all of them at once in an aggressive pheromone-spreading raid. Then, wait for the scent to travel, sit back, and enjoy the chaos.


Send a swarm of bees, wasps, and hornets to sting them in the nose, mouth, and throats. This will cause their airways to swell and close and they will suffocate. Swarms of gnats clog their eyes and ears. Fire ants crawl under the armor and drive the knights insane with itching and burning.

As they fall to the ground, carrion insects quickly reduce them to skeletons, which will spread fear in those sent to bury the dead.


If you need to break an assault then rely on wasps, hornets and the like do not forget horse flies and friends to keep mounts busy).

While you are concealed send disease carriers such as:

  • Tsetse fly
  • Malaria infected anopheles
  • Bubonic pest fleas

While knights are distracted hit them hard with venom spiders, scholopendras and similia.

In the meantime "thank" the "nice peasents" you previously helped by sending hordes of locusts to destroy their fields; it's very likely they'll ask the king to withdraw the knights.


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