Cordyceps: Could the Real 'Last of Us' Zombie Fungus Actually Infect Humans?
Many assume that growing older means gaining full control over their lives, but the concept of true autonomy is more complicated. The belief in free will is deeply rooted, yet history and nature both challenge the idea that we are always the authors of our own actions.
Examples from the natural world show that control can be an illusion, as seen in creatures whose bodies and behaviors are hijacked by parasites and fungi. These cases provide a striking reminder that forces beyond our awareness can steer living beings in unexpected ways.
Key Takeaways
Autonomy is more limited than many believe.
Nature contains real-life examples of behavioral control.
Parasites and fungi can dramatically influence their hosts.
The Illusion of Free Will
Perceived Authority in Growing Up
Becoming an adult is often linked with the belief that one finally gains sovereignty over their choices. Examples like selecting meal times or bedtimes support this notion. Yet, daily life still demands compliance with outside rules from governments, workplaces, and personal relationships.
Despite the appearance of choice, there are multiple systems enforcing behaviors. Taxes must be paid, lockdowns must be observed, and social expectations often outweigh individual desires. The feeling of true autonomy often clashes with these real-world constraints.
Views on Independence from Philosophy
Philosophers have long discussed whether people genuinely possess free will or simply follow predetermined paths. The debate considers if decisions are authentically self-directed or shaped by external influences. This topic stretches back centuries and is frequently revisited.
Humans tend to prefer seeing themselves as active decision-makers rather than passive participants in life. Accepting the lack of real control challenges the basic idea of personal responsibility and self-identity. This tension reflects an ongoing conflict between the comfort of autonomy and the reality of external steering forces.
Real Creatures Controlled by Other Organisms
Animal Behavior Rewired by Parasites
Many parasites in nature can alter the behavior of their hosts in ways that benefit the parasite but harm the host. For example, the spider Plesiometa argyra becomes a pawn for a parasitic wasp. After being stung, the spider has wasp larvae attached to its body, which begin to feed on the spider's bodily fluids.
After two weeks, the spider undergoes a drastic change. It stops its normal web building and constructs a new, unusual web structure. This final act ends with the spider being consumed alive by the larvae. The wasp offspring then build their cocoons, using the spider's last creation as their support.
Parasite-Host Manipulation Examples
• Plesiometa argyra (spider)
Host: Plesiometa argyra (spider)
Parasite: Parasitic wasp larvae
Effect on Host: Forced to build special web; eaten by larvae
• Woodlouse
Host: Woodlouse
Parasite: Starling gut parasite
Effect on Host: Moves to exposed spots, increasing chance of predation
• Snail
Host: Snail
Parasite: Green-banded broodsac
Effect on Host: Eye stalks invaded, making them more visible to birds
Other animals, like the woodlouse and certain snails, also fall victim to parasites that compel them to expose themselves to predators. This often results in the parasite re-entering its preferred host’s digestive system through the food chain.
Mother Nature’s Unseen Control Over Actions
Mother Nature’s influence can extend deep into the animal kingdom by means of pathogens and fungi. Fungi from the genus Cordyceps are notable for their methods: they infiltrate insect bodies and release chemicals that alter the host’s behavior.
A striking example is the ant infected by Ophiocordyceps unilateralis. After being infected, the ant is driven to climb vegetation and bite down firmly before dying. Fungal growth soon erupts from the ant’s body, spreading spores to new hosts on the forest floor below.
Common Parasitic Fungi and Their Methods
Beauveria bassiana: Penetrates insect exoskeletons, kills the host, then produces spores.
Cordyceps species: Hijack neurological functions, causing insects to perform actions that support the fungus’s propagation.
Beauveria bassiana is so efficient that it is used as a biological insecticide. In contrast, Cordyceps species are more specialized and directly commandeer the movements of particular insect hosts before killing them. This form of host control is prevalent across various ecosystems, revealing just how often life in nature is manipulated by other living things.
Zombie Spiders: Subjugation by Parasitic Wasps
Silver Orb-Weaver Spiders and Their Parasitic Invaders
The spider species commonly known as the silver orb-weaver is regularly targeted by a certain parasitic wasp. The wasp approaches its victim and delivers a paralyzing sting, rendering the spider immobile. After immobilization, the wasp deposits its larvae onto the spider’s body, and the unfortunate arachnid becomes an unwilling incubator.
Silver orb-weaver
Species: Silver orb-weaver
Invader Type: Parasitic wasp
Method of Parasitism: Paralysis and egg laying
The wasp’s larvae attach themselves externally, creating small holes in the spider’s abdomen through which they feed on bodily fluids.
Larval Manipulation of Spider Behavior
For the initial two weeks, the infected spider continues its daily routines almost unaffected, unaware that it is sustaining a growing parasite population. Over time, the larvae somehow alter the spider’s instincts, prompting it to spin a dense and sturdy web platform—unlike typical orb webs usually created by this species.
Notable changes induced by larvae:
Sudden abandonment of regular web maintenance
Construction of an atypical silk platform
The manipulated spider dedicates itself to building this specialized structure, often during its final hours. Once the platform is finished, the larvae consume the spider, using the newly woven web as an anchor for their cocoons. The cycle ends with the larvae safely suspended, ready to begin the next stage of their development.
Parasites Influencing Insect Behavior
Pill Bugs and Parasites from Bird Droppings
Woodlice, known more commonly as pill bugs, often consume bird feces, especially from starlings. Starlings commonly carry a parasite that does little harm to the bird but poses a real threat to the pill bug.
Once the parasite enters the woodlouse, it manipulates the insect’s behavior. The pill bug is compelled to venture into open, exposed locations, which increases its visibility.
Key points:
The parasite’s goal is to return to a starling host.
Exposed pill bugs are more likely to be eaten by birds, continuing the parasite’s cycle.
Broodsac Parasites and Snail Manipulation
Some snails, after ingesting bird droppings, become hosts to the green-banded broodsac parasite. Instead of simply affecting the snail’s routine, the broodsac invades the snail’s eyestalks, expanding and throbbing to mimic a caterpillar.
This transformation attracts the attention of birds, leading to the snail—and the parasite within—being eaten.
How the broodsac manipulates:
Occupies and alters the snail’s eyestalks
Creates visible, pulsating structures that look like prey
Increases chances of the snail being noticed and consumed by birds
Visual summary:
Snail eats droppings → Broodsac larvae enter snail → Larvae invade eyestalks → Eyestalks pulsate visibly → Bird eats snail → Cycle restarts
Fungi: The True Masters of Manipulation
Understanding the World of Fungi
Fungi make up one of nature’s key kingdoms, sitting alongside plants and animals, with a variety covering yeasts, molds, and mushrooms. Unlike plants, fungi cannot make their own food; instead, they break down and absorb nutrients from other substances. Their presence is everywhere—from forest floors to cupboards—each species playing its role in the broader ecosystem.
Fungi Classification and Roles
• Yeasts
Fungi Types: Yeasts
Examples: Baker's yeast
Role: Fermentation, baking
• Molds
Fungi Types: Molds
Examples: Penicillium
Role: Antibiotics, decay
• Mushrooms
Fungi Types: Mushrooms
Examples: Shiitake, oyster
Role: Decomposition, food
• Parasitic Fungi
Fungi Types: Parasitic Fungi
Examples: Cordyceps, Beauveria
Role: Infect insects, control
Despite their reputation for causing rot and mildew, fungi also offer key services—from recycling nutrients to producing vital medicines.
Insect-Controlling Fungi: An Introduction
There’s a particular group known as entomopathogenic fungi, famous for infecting and often killing insects. Two standout examples are Beauveria bassiana and cordyceps species.
Beauveria bassiana penetrates the hard outer shell of insects, multiplies inside them, and causes death within days. Afterward, the fungus grows out of the body and releases spores to find new hosts. This fungus is even used by humans as a natural pesticide because of its effectiveness against pests like aphids and termites.
Cordyceps fungi go a step further. They release chemicals that alter the behavior of their insect hosts, effectively turning them into “zombies.” Each cordyceps species usually targets a specific insect. The most famous, Ophiocordyceps unilateralis, infects ants and manipulates them into climbing plants and attaching themselves before dying, allowing the fungus to spread its spores from a high vantage point.
Notable Cordyceps Targets:
Butterflies
Dragonflies
Cockroaches
Caterpillars
Wasps
Ants
The list below highlights some relationships:
• Ophiocordyceps curculionum
Cordyceps Species: Ophiocordyceps curculionum
Common Host: Weevils
Notable Region: Central/South America
• Ophiocordyceps sinensis
Cordyceps Species: Ophiocordyceps sinensis
Common Host: Caterpillars
Notable Region: Himalayas
• Ophiocordyceps humbertii
Cordyceps Species: Ophiocordyceps humbertii
Common Host: Wasps
Notable Region: Brazil
• Ophiocordyceps unilateralis
Cordyceps Species: Ophiocordyceps unilateralis
Common Host: Ants
Notable Region: Worldwide
Fungi like these are not just killers; they display an almost engineered capacity to manipulate insect behavior, ensuring their own survival and propagation with startling precision.
Beauveria bassiana: Natural Insect Killer
How the Fungus Invades and Destroys Insects
Beauveria bassiana is a soil-dwelling fungus that attacks insects and other arthropods. It starts by penetrating the tough outer layer of its target, growing inside until the insect dies within days. After the host dies, the fungus takes over the body, covering it in spores that drift away to infect new victims.
Key Steps in Infection:
Spores attach to insect's surface
Fungal threads enter the exoskeleton
Fungus multiplies inside, causing the insect’s death
Spores emerge on the corpse, continuing the cycle
Use in Controlling Insect Numbers
Because of its lethal effects on certain insects, Beauveria bassiana is widely used as a biological insect control method. It is especially effective against pests like termites, aphids, and beetles, offering a natural alternative to chemical pesticides.
Notable features:
Targets specific pests without harming humans
Used in agriculture and pest management
Considered “friendlier” compared to other entomopathogenic fungi due to its targeted impact
Cordyceps: Fungi That Control Their Hosts
Range and Types of Cordyceps
Cordyceps fungi exist in regions ranging from humid tropical forests to more temperate zones across the globe. Scientists have identified at least 600 separate species, with each kind generally focusing on a specific insect or arthropod host.
Cordyceps can be found targeting everything from butterflies, dragonflies, and cockroaches to various beetles.
Notable species include:
• Ophiocordyceps curculionum
Species Name: Ophiocordyceps curculionum
Primary Target: Weevils
Region: Central and South America
• Ophiocordyceps sinensis
Species Name: Ophiocordyceps sinensis
Primary Target: Caterpillars
Region: Himalayas
• Ophiocordyceps humbertii
Species Name: Ophiocordyceps humbertii
Primary Target: Wasps
Region: Brazil
Most Cordyceps species have adapted to their host's biology, ensuring survival and spore distribution.
Mind Control in Insects
What makes Cordyceps especially notable is their ability to manipulate the actions of their hosts. Once the fungal spores enter the insect, enzymes break down the tough exoskeleton and the fungus moves inward, eventually releasing chemicals that alter the host's normal behaviors.
A classic example is Ophiocordyceps unilateralis, which infects ants. After infection, the ant leaves its colony, climbs vegetation, and bites down on leaves or branches. This fixed position allows the fungus to grow out from the insect and release spores, increasing the chance new victims come in contact with the fungus.
This pattern of behavioral manipulation isn't unique to ants. Other Cordyceps species can influence wasps, caterpillars, and beetles to act in ways that benefit the fungus, often at the expense of the host.
Some common insect responses include:
Climbing to elevated positions
Biting down on specific surfaces
Remaining immobile for extended periods
The fungus then completes its life cycle by spreading spores, often showering them onto new potential hosts below.
Ophiocordyceps unilateralis: The Ant Zombie Maker
How the Fungus Takes Over Ants
Ophiocordyceps unilateralis specializes in infecting ants using powerful enzymes that break down chitin, the tough material in the ant's exoskeleton. Once the fungus gains entry, it targets the ant's nervous system, ultimately controlling the host’s actions. The infected ant is compelled to climb vegetation and bite down tightly to a leaf or branch.
Below is a brief list of the takeover process:
Enzymes dissolve the ant’s protective shell
The fungus invades neural tissues
Behavioral control leads the ant to a high location
The ant secures itself with a death grip
Growth and Spreading Spores
After the ant clamps onto vegetation, the fungus begins a new stage. It slowly grows through the ant’s body and outward. Eventually, fruiting bodies burst through the exoskeleton, releasing spores into the air.
Spore dispersal process:
• Attachment
Step: Attachment
Description: Dead ant remains attached in an elevated spot
• Fruiting
Step: Fruiting
Description: Fungi structure emerges from the ant's body
• Release
Step: Release
Description: Spores are ejected into the surroundings, often falling on other ants
This infection cycle is highly effective. Ants passing below may come into contact with the spores, allowing the fungus to infect new hosts and continue its spread through the colony.
Summary: Real-World Occurrence of Zombie Phenomena
Real-life examples of zombification are widespread across nature, taking on various forms and affecting many different creatures. Parasitic wasps, for instance, use spiders both as hosts and caretakers for their young, manipulating the spiders’ behavior until the larvae are ready to emerge. Pill bugs and snails are also hijacked by parasites that alter their actions to ensure the completion of the parasite’s life cycle.
Fungi, especially the entomopathogenic types, are among the most notable real-world agents of zombification. The genus Cordyceps contains hundreds of species specializing in infecting specific insects. These fungi take control of their hosts’ nervous systems, effectively turning them into tools for spreading fungal spores.
Examples of Real-Life Zombie-Inducing Agents
• Parasitic Wasp
Organism/Agent: Parasitic Wasp
Host Organism: Spider
Mechanism of Control: Paralysis, behavior manipulation
Outcome: Spider builds web, becomes food for larvae
• Bird-Gut Parasite
Organism/Agent: Bird-Gut Parasite
Host Organism: Pill Bug (Woodlouse)
Mechanism of Control: Behavioral changes for exposure
Outcome: Eaten by birds, parasite returns to bird
• Green-Banded Broodsac
Organism/Agent: Green-Banded Broodsac
Host Organism: Snail
Mechanism of Control: Grows in eyestalk, visual mimicry
Outcome: Snail eaten by bird
• Beauveria bassiana
Organism/Agent: Beauveria bassiana
Host Organism: Insects/Arthropods
Mechanism of Control: Internal infection, spore dispersal
Outcome: Death and fungal growth
• Cordyceps fungi
Organism/Agent: Cordyceps fungi
Host Organism: Various insects
Mechanism of Control: Chemical manipulation of brain
Outcome: Host climbs, dies, fungi disperses spores
These cases show that nature’s version of “zombies” is both diverse and persistent. Whether through bacteria, fungi, or parasites, many organisms have evolved highly specialized methods to commandeer the bodies and behavior of other species for their own benefit.
Key Points:
Real-life zombification often serves the reproductive or survival needs of the controlling organism.
Fungi like Cordyceps and Beauveria bassiana stand out due to their complex life cycles and global occurrence.
Behavioral manipulation by parasites can be subtle or dramatic but is always tailored to maximize the parasite’s transmission or development.
While cinematic zombies belong to fiction, the biological world is filled with remarkable and disturbing examples of mind control and involuntary servitude.
