The zombie apocalypse storyline of the popular video game and TV series The Last of Us is presented as a work of fiction. However, there is a real organism that almost perfectly mimics the mind-control fungus that infects zombies in The Last of Us. In tropical forests across the globe, you’ll find it hijacking ants’ brains, taking over their behavior and turning their bodies into launchpads for new spores.
Similarly to the fungus in the TV show, it’s called Ophiocordyceps — and its abilities are so strange that researchers once struggled to believe what they were seeing. Although it sounds like a monster from a video game, the fungus is very real and far more ancient than humans.
What Exactly Is The Mind-Control Fungus?
Ophiocordyceps is a genus of parasitic fungi. It’s best known for infecting ants, especially carpenter ants. However, unlike most fungal infections we’re acquainted with, it grows inside the insects it infects, rather than on the surface of their bodies. The fungus infiltrates the ant’s body, spreads through its tissues and, most disturbingly, eventually goes on to manipulate its behavior.
Some species complexes of the fungus (with Ophiocordyceps unilateralis being the most well-known) are often referred to as the “zombie-ant fungus.” However, this nickname barely captures its ancient complexity. A 2023 study published in IMA Fungus notes that there are dozens of Ophiocordyceps species in existence. Each different species is evolutionarily adapted to a specific kind of insect host, almost like a biological lock-and-key system.
As the 2023 study notes, some key features of the six ant-infecting Ophiocordyceps fungi are that:
- They only infect specific species of ants
- They need a precise environment (usually humid tropical forests)
- They cannot complete their life cycles without altering the ant hosts’ behaviors
- They evolved millions of years before humans even existed
It’s important to note that, despite its strange behavior, this genus of fungus isn’t “intelligent” in any human sense, nor in any sense that shows and movies like The Last of Us would lead you to believe. That said, evolution has nevertheless shaped it into one of the most sophisticated manipulators in the natural world.
How The Mind-Control Fungus Infects Its Host
An Ophiocordyceps infection starts with a single one of its spores landing on an ant’s body. These spores drift almost invisibly through the forest air, in a similar manner to pollen, until they eventually land on a host. Once there, the spore attaches itself to the ant’s exoskeleton and uses enzymes to dissolve a minuscule entry point into the inside of its body. Thereafter, the fungus slips inside and begins to grow.
A 2020 study published in G3 Genes|Genomes|Genetics found that, during these early stages, the fungus actually avoids causing any damage to the ant’s vital organs. This, in turn, allows the ant to continue functioning as it normally would. However, during this period of regular functioning, Ophiocordyceps spreads through the ant’s body in fine, branching filaments. In other words, it feeds undetectably on the ant’s insides while slowly preparing for takeover.
Contrary to popular culture plotlines, the fungus does not actually take direct control of the ant’s brain. Instead, as the G3 study explains, it actually grows around the ant’s muscles. By secreting a special combination of chemicals, the fungus is then able to override the ant’s normal behavior.
Instead of envisioning it as something that infects the ant’s brain in order to literally “control” its mind, the reality might just be creepier. That is, it controls the ant like a puppet by pulling strings anchored to its muscles, rather than merely rewriting thoughts — and there’s nothing the ant can do to stop it.
Specifically, this manipulation occurs when:
- The fungus releases chemicals that alter the ant’s muscle contraction
- It disrupts the ant’s internal clocks and sense of direction
- It forces the ant to leave its colony, climb vegetation and clamp onto a leaf or twig
This final step is what biologists call the “death grip,” and it’s both the most important and disturbing stage of all.
Why The Mind-Control Fungus Forces The Death Grip
The death grip is not a random part of the process of infection. In fact, by forcing the ant to grip down on the desired leaf or twig, Ophiocordyceps leads its host to the perfect location for it to grow and spread. A 2023 behavioral analysis published in Scientific Reports showed that the heights and orientations chosen by infected ants are remarkably consistent — so consistent that scientists suspect the fungus manipulates not only the ant’s muscles, but also its internal “GPS.”
This location matters because:
- The humidity at this height keeps the fungus from drying out
- The positioning gives the fungus the ideal amount of space to grow its reproductive structure
- Spores released from this position fall directly down onto other ants trailing below.
Most eerily, once the ant is in the death grip, it dies soon after. After the ant is dead, the fungus is then free to consume the remaining tissues. Thereafter, it constructs a stalk-like structure that bursts from the back of the ant’s head — something that was actually replicated quite well in The Last of Us.
The stalk then rains spores onto the forest floor, which enables the zombie cycle to start over again.
Why This Fungus Evolved Mind-Control
Ophiocordyceps’ mind-control behavior isn’t evil or horrific in the way popular culture portrays it to be, because it actually isn’t “intentional” at all. Because Ophiocordyceps doesn’t have a “brain” in the same way we do, this means that it doesn’t afflict its victims with harm in mind. In reality, this process is just the result of millions of years of natural selection. The strains that best positioned their hosts to spread spores survived; those that didn’t died out.
Over time, this relentless pressure refined the fungus into a remarkably precise manipulator. It evolved highly specialized chemical cocktails capable of altering ant behavior, along with tissue-specific enzymes that keep the host alive just long enough to reach the ideal location.
Importantly, note that it is in no way, shape or form possible for Ophiocordyceps to infect a human. Our body temperatures, immune systems and cellular structures are fundamentally incompatible with this fungus. This means that, despite what horror stories suggest, we are actually far from what the ideal host looks like.
Instead, the fungus can only recognize and infect specific species, which means that our human biology is completely foreign to it. In fact, our body temperature alone is high enough to destroy it, and our immune systems are likely to attack it almost immediately post-infection.
Because of this, Ophiocordyceps lacks any ability whatsoever to manipulate human nerves or muscle tissue. In other words, the idea of “zombie humans,” infected by mind-control fungus, is purely a work of fiction.
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