The Wold (Forest) is one vast, interconnected, possibly digital mind. The mind is primarily built of one cloned individual of a single plant species, but there are over a dozen 'helper' sub-minds and hundreds of symbiotic plants, fungi and insects that play a vital role it its optimal functioning.

Now I'm undecided whether this vast network arose naturally, was built by 23rd century eco-fanatical AIs or by a human xenobiologist called Deidre Skye. I'm undecided whether it's a dark swamp or a bright and sprightly forest. I'm also undecided on the thinking speed: it could ponder things with Ent-like slowness or its thoughts could reverberate across the network in a millisecond.

Regardless, I've hit a limitation that I need Worldbuilder support to overcome. Since the Forest will always be threatened by various plants and animals, it requires mobile minions to enforce its will. Ideally, these would range in size from insects to massive beasts, but I'm open to more restrictive solutions too. Now how would a sentient forest control and direct such a host of animals?

Good answers would have:

  • a signalling mechanism, perhaps allowing for relative speed;
  • a way to use a subclass of minion to interact with the (as usual) hapless human POV character;
  • a way to ensure minion obedience, perhaps to the point of self-sacrifice.
  • $\begingroup$ Are these mobile minions part of the solution, i.e. designed/evolved alongside the hive-mind plants, or separate to it, i.e. controlled by the plants, or does it not matter? $\endgroup$
    – Monty Wild
    Commented Feb 23, 2015 at 1:13
  • $\begingroup$ @MonyWild I'm thinking the basic types might predate it, especially if it is a construct. It has had centuries of selective breeding to play with these forms, however. $\endgroup$ Commented Feb 23, 2015 at 1:15
  • $\begingroup$ So, the mobile minions were not designed alongside the plants, but the plants may have been designed/evolved to take advantage of them. I'll include that in an answer when I can. $\endgroup$
    – Monty Wild
    Commented Feb 23, 2015 at 1:18
  • 1
    $\begingroup$ +1 for the SMAC reference - you would love Greg Bear's novel Legacy - about a somewhat similar idea though natural and directed by Lamarckian evolution. $\endgroup$ Commented Feb 23, 2015 at 13:52
  • 1
    $\begingroup$ @MarchHo, thanks! Also, it's the Wold, not the World, so the sentient heart of the forest might be as little as a few dozen kilometers across. Wold is an old English name for forest, like Wald in German. $\endgroup$ Commented Mar 2, 2015 at 13:21

11 Answers 11


Believe it or not, you don't have to go too sci-fi to have plants exerting a massive influence on their environment. Some plants can be very aggressive, and most plants can be very passive aggressive.

Weapons at a plant's disposal (in the real world).

  • Symbiosis
  • Pollen
  • Sap and essential oil
  • Nectar
  • Fruit
  • Seeds
  • Growth
  • Reflexes
  • Lifecycle
  • Pheromones

Plants are the very basis of every food chain in the web, period. That puts them in a great position to influence even top predators. Animals eat leaves, shoots, nectar, fruits and seeds of plants, and the plants control when to produce each of these commodities. If you have a massive forest of even barely intelligent trees, you can control the migration of all animals within it by making leaves fall in one section, pollen release in another and fruit form in a third.

Many animals as part of their nature husband the plants that feed them. Squirrels bury nuts/seeds, apes and monkeys throw fruit (even when they are hungry).

Plants release oils when they are competing with other plants that inhibit their growth or even kill them. They can also just grow taller and block out their sunlight.

Plants can grow at phenomenal rates. Some edible stalks and fruit can grow by 8-12 inches per day. That's almost 30 c.

There are plants that release a pheromone that mimics those released by animals so that for instance, wasps will be attracted when the trees are being attacked by things that wasps eat or breed in.

I can't find it documented anywhere, but I have seen strawberry plants in planter boxes send out offshoots ONLY in the direction of another planter full of dirt.

To attract various types of insects, a tree might produce more nectar, more pollen, more fruit, or change colors in a given wavelength of light. For instance, a flower full of nectar looks just like an empty flower to us humans, but bees can see into the UV spectrum just far enough that there is a dramatic color change.

Mimosas and venus fly-traps will close up when touched, many plants will exude noxious oils, or fling seeds on contact, others will reach out vines and grasp firmly onto obsticles, and many plants supplement their nutrition by killing animals and using their decaying bodies as fertilizer.

Plants, even as tiny as grass can break slabs of concrete and reduce man made structures to base components in mere decades.

If the entire system could be likened to a single creature, the loss of a 'cell' is worth the survival of the whole. Trees could die off for many reasons. They could dry up to increase the risk of fire in a given area, drop branches or heavy seed pods to actively attack surface dwelling pariahs, but at the same time, dead trees offer homes and even food to other creatures they may want to promote. Your sentient trees could have gardens of fungi, just by growing and dying in the correct timeframes. They can purposely irritate these same fungi to cause them to release spores by dropping leaves or growing shoots through them.

Plants can hibernate like nobody's business, surviving intense cold and long periods of drought. Viable seeds have been planted after 30,000 years.

Don't forget that they also control oxygen production. Their respiration is a chemical bi-product of photosynthesis, so they could potentially halt it entirely and make things very difficult for larger creatures like us.

None of what I've added here inhibits any of your ideas on fast thinkers versus slow ones, or how intelligent they have to be. The main thing is they just need to be varied, with control over most if not all things on the above list. They can act on their own, or influence creatures that live within or nearby them to act for them. Heck, they may just be in charge of this world already...


Inherent Programming

Rather than directly controlling the animal minions, why not create them with some inherent programming that gives them an urge to defend the forest? Essentially, they'd be bred to behave in an aggressive manner towards anything that threatened the forest.

This would range from basic animalistic territorial instinct for animals like bears and crocodiles, to religious and spiritual ties to the forest for the ultimate forest defenders: the elves. Elves could guard the forest out of loyalty and religion, with perhaps some additional instinctive barbs that keep them around as loyal forest defenders. Elves may feel uneasy when they venture outside of the forest, and may even feel physical pain when they see someone damage the forest plants.


The forest could further control its inhabitants through the usage of pheromones. Depending on what the forest needed, it could release different chemicals, each of which would affect the behavior of the animals in a different way. Anger or happiness, for example, could be used to either inspire defensive behavior or else to reward creatures for protecting the forest.

Pheromones could also be used to identify forest dwellers to one another. If the forest constantly gave off a scent that would settle on anyone living there for a long time, all of the forest creatures could identify intruders as anyone who smells different. If the forest wants to be a bit more proactive, other scents could be sprayed on intruders, acting like antibodies and painting targets for the minion animals to attack.

All of this would lead to a system of forest defense that wouldn't, for the most part, require any active thought or action on behalf of the forest. Animals would patrol about, acting like animals, and eating anything hostile that wandered in. The elves would deal with any larger threats that presented themselves, only needing to consult the Wold in times of dire emergencies.

The Wold would be left to do as it pleased, not having to worry about its own defense. Perhaps it spends its time astrally projecting its mind across the world to learn more about what lies outside the borders of its mighty trunks.

  • $\begingroup$ This is a little light on the bandwidth that would be necessary to distinguish between servitor and non-servitor animals, and harmful and non-harmful actions. $\endgroup$
    – Monty Wild
    Commented Feb 23, 2015 at 2:16

I like the basic idea behind @Monty Wild's Direct parasitic neural control answer, but I think there's room for improvement.

Having your plants control the animals directly strikes me as improbable, inefficient, bug-prone and potentially vulnerable to jamming. So I'd like to propose an alternative:

Direct parasitic neural conditioning

Instead of taking over the entire neural system - an insanely complex task - instead we have a parasite that only invades and attaches itself to specific portions of the animal's brain, namely the pain, pleasure, emotion, and sensory areas (still an extremely complex task, but orders of magnitude easier). Then the parasite will use conditioning to mold the animal's behavior, over time, into what it wants. For example, an infected human might feel pain if he tried to use an axe on a tree, or if he was about to over-hunt an area. An infected bear would feel pleasure going toward areas the forest wants guarded, and hate and hunger when it sees an enemy of the forest.

The nice thing about this is that after enough conditioning over time, most controlled animals won't need much control at all. Just the occasional re-enforcement, and now usually they do what the forest wants without any direct input. This leaves the forest time to do what it wants to do, instead of wasting it controlling all these meatbags. In emergencies the forest could still summon animals to certain areas by making them feel "need", for defense and such.


Direct parasitic neural control

A single-species organism capable of networking into a hive mind capable of controlling other species including animals would by necessity have to think as fast as the animals it controls, or else those animals would be more likely to escape or circumvent that control, or would simply be uncontrollable. Think of the complexities of controlling an insect: they have so little mind that they couldn't be set a task, they would have to be controlled precisely right through execution to completion. This problem wouldn't be any less a problem as larger animals were involved either, as there is no guarantee that these proxy animals would have enough brains to understand the instructions, in fact it would be safer to assume the contrary.

So, the question is, how a bunch of interconnected, thinking plants could control animals. Whatever it was would need a bandwidth sufficient to get the animals to do whatever was needed, down to the level of "Move these muscles this way", as the plants with their undoubtedly vast intelligence would have a far better idea of what they wanted done than trusting anything but the simplest tasks to the instincts of some dumb animal.

In this answer, I proposed radio-based telepathy. It may well be that this is how these plants communicate when separated, though when in direct contact, they could potentially communicate faster via hard-wired means. This would also provide a potential means by which the plants could control their servants.

If we presume that these plants are designed/evolved to be immunologically neutral to many species that they may control, they could use the animals they control as an important part of their life cycle, and infection of an animal would be a necessary step in the growth of the plant. The means of infection could be many, from ingestion of the plant's fruit to a non- or semi- sentient mobile transmission agent like a wasp (that is a homozygous mobile form of the heterozygous sessile plant) that mates and injects potential hosts with a newly-formed seed.

In any case, having achieved infection of a host animal, the plant parasitises the animal's brain and intrudes its own neural connections on the animal's, as well as forming a radio transceiver organ to link with the rest of the plant hive mind. This would requiring a somewhat larger host animal, probably at least mouse-sized. It might be possible to use a lower bandwidth connection and signalling method, such as audible or visible signalling, and rely on the parasitic-plant's instinctive actions, though this would not be as versatile as a high-speed connection. Regardless, there would be a period of ineffectiveness while the seedling grew into the host's brain and learned to control it, during which the animal would be allowed to act normally. Then, once control had been established, the animal would be available for colony defence and whatever other projects the plant hive mind might have.

So, we have animals that are gradually taken over by the plants seedlings, which can eventually see and act using the parasitised animals. However, whether or not the parasitised animal is killed while undertaking its tasks, the growth of the plant might eventually kill the host animal. Anyway, at the death of the host animal, the plant would use its body as a source of nutrients to fuel rapid growth into the adult, sessile plant form. Naturally, larger host animals would provide a longer useful lifespan and a bigger growth boost.

With the plants' sentience on their side, the host animals may even benefit if the plants allowed them to breed, and assisted in the protection of their offspring, letting the host animals raise more offspring to adulthood than would otherwise be the case, before their inevitable death.

  • $\begingroup$ I like most of this, but I don't think it necessarily follows that insects would need to be directly controlled to enact complex behavior. Eusocial insects manage very complex tasks as groups, and even simply social ones (like cockroaches) respond in complex ways to environmental cues. And, existing real-world parasites can already get their animal hosts, from insects on up, to behave in very unusual fashions. It's more a matter of knowing what neural buttons to push to get the response desired. $\endgroup$ Commented Feb 23, 2015 at 3:35
  • $\begingroup$ @plagueheart, eusocial insect behavioural complexity is defined by predetermined neural networks with very little scope for variation. These insects become confused when presented with scenarios outside their predefined set of responses. My answer specifies a more intelligent, problem solving approach that would necessitate a relatively complex neural network too big to fit in the body of anything but a large insect or something bigger. If you were prepared for a simplistic, canned response system, you could infect smaller insects. $\endgroup$
    – Monty Wild
    Commented Feb 23, 2015 at 6:26
  • $\begingroup$ I suppose it would have been better to say, "Why would you need insects to engage in more complex behavior than they're already capable of?" Infected ants or bees could still provide useful functions, both in maintenance of the forest and deterrence of intruders, without having to have their behavior precisely scripted by the controlling entity. They've already got useful predetermined responses to predator intrusion, environmental hazards, etc. etc. $\endgroup$ Commented Feb 23, 2015 at 6:38

Indirect control by exploiting the natural behavior of animals.

Suppose the most dangerous creature in the forest are very aggressive, badass murderbears. They are very dangerous, but there aren't many of them in the forest and they are solitary creatures, so you usually never encounter more than one at once. That means they are a manageable risk when traveling through the forest in a well-armed group.

Suppose the favorite food of the badass murderbears are lumberjacks and cute, fluffy bunnies which live everywhere in the forest.

Suppose the main food source of the fluffy bunnies is the symbiotic fungus which is part of the neural network of the forest overmind.

  1. the forest overmind notices that humans start to cut down trees in one area of the forest and perceives this as a threat.

  2. it selectively kills off all the neural fungus in the surrounding region, but even increase the growth in the logging area itself.

  3. This causes all the fluffy bunnies to migrate to the logging area. The lumberjacks won't be bothered much by this at first, because the bunnies are cute and harmless. Besides, they are eating all the fungus which started to make their work harder.

  4. But without any fluffy bunnies in their usual territories, all the badass murderbears will become hungry. So all the badass murderbears in the region will follow the fluffy bunnies into the logging area.

  5. Suddenly the lumberjacks are confronted with a large number of badass murderbears which seemingly came out of nowhere. They fight bravely, but they can not handle that many at once. All of them are brutally slaughtered.

Oh, how foolish they were, trying to exploit this intricate ecosystem without trying to understand its complex workings.

  • $\begingroup$ I'm almost tempted to +1 just for badass murderbears as a description alone, but this is also an excellent solution without requiring the forest to ASSUME DIRECT CONTROL. $\endgroup$ Commented Feb 24, 2015 at 0:03
  • $\begingroup$ Won't it take time though? A team of lumberjacks could cut down a few dozen trees, then scarper off. $\endgroup$ Commented Jul 29, 2017 at 4:57

There is something akin to a religious worship involved.

Lower animals, insects and such are controlled by scents and pheromones, and their autonomous "defend the nest" or "defend against predator" reactions are activated remotely by you're Wold.

Higher animals, with significant brains, their brain patterns are molded from birth by the Wolde with neuroactive chemicals, such that they love it unconditionally, fully and totally. These could be ferocious beasts or even sentient beings, native to the forest. Given this worshipful love, the Wolde would hardly need to influence them much, except by releasing chemical triggers into the air if it thinks the brainy servants aren't acting as it wants them to.

  • $\begingroup$ I like your spelling of the Wolde better. $\endgroup$ Commented Feb 27, 2015 at 1:40

Directed evolution + classic conditioning.

Somewhere deep in The Wold is the "breeding warrens", where the mind can directly supervise the breeding and training of it's minions. I'm thinking something perhaps a cubic kilometer, with various faculties such as nurseries, feeding, and training areas. Perhaps using the pheromone idea so that the soldier minions can be breed/conditioned to attack those without the pheromone, plus some degree of autonomy (something that smells right but is doing bad things, akin to cancer). In that respect, perhaps the soldiers are best thought of as something like white blood cells (Killer T cells)

New species can be introduced to the Wold by the minions gathering the young, and The Wold can put them through the breeding warren process a few hundred generations to see if they are of use.

  • $\begingroup$ ...and I suppose humans could be put through the process to obtain "elves". $\endgroup$
    – JasonS
    Commented Mar 2, 2015 at 4:55

For a completely different pace, consider a more peaceful ecosystem.

Does the control have to be so absolute? Consider the fundamental nature of what an ecosystem is. Every plant and animal is acting on its own interests, and yet everything works together to remain in harmony. If I were setting a living forest to fight in, I would rely less on absolute control and more on convincing the animals and plants to act in unison.

This would allow my forest to communicate in more calm, subtle ways. An unusual bloom on the shady side of the trees calls animals to action. Withering blooms on the bright side is a sign to nurture life, instead of fight. (These, of course, are related to the oldest meanings for yin and yang). Why should I tell my animals to attack, when I can instead have them use their own judgement. Of course, as the forest, I would bring my own vote to the table; they should be a bit more aggressive in regions blooming with Bella Donna (quite the nasty flower, if you research it). Torn down forest would be populated with Oleander as a sign that rebuilding is welcome (Oleander was the first flower to bloom after the nuclear bombing of Hiroshima).

This subtle approach yields a subtle power. I am not enslaving the animals, I am bringing them into coherence with my desires. This way, I don't have to have lighting fast response times to control my minions with perfect precision. I ask each and every one of them to not only bring their body to the fight, but their mind as well. And when the fighting is over, I haven't created any twisted forces to undo. All I've done is simply bring forth the raw power of nature, as I always have.

Why send 10 tons of animals full tilt to do what can be accomplished by 10 million tons of nature all taking one step to the right, in terrifying accord.


Chemicals like pheromones. Think about ant colony serving (also) to a plant.

If all is peachy, ants go around their business, growing their colony.

Is something damaged plant, one kind of chemical signal can be extruded by damaged part of plant, and protectors will attack whatever is around other part, and extrude signals to recruit more attackers.

That will include also self-sacrifice.


Just to add to the ideas already suggested, the trees intelligence may not be entirely aware of the animals, they'd be like antibodies in our body, they'd die and fertilize the trees, live and feed off the older and damaged leaves, attack predators instinctively, and the trees may only be vaguely aware of their presence, in a way like garbagemen and postmen are "invisible" (mail arrives, but you don't necessarily see a postman deliver it).

Just my $0.02


Perhaps the forest could communicate with a person who has trained animals to obey commands. The forest could tell the human about danger and/or directly give the animals commands.

Alternatively, the animals could directly communicate with the forest and be one of the helper sub-minds.

  • $\begingroup$ Can the downvoter please explain why? $\endgroup$ Commented Dec 4, 2017 at 3:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .