When Ants Become Suicidal Zombies: The Zombie Ant Fungus Are A Natural Horror Story
A few days ago, it happened. My wife and I were sitting on the couch in the evening, trying to watch a reality TV show. And then it came. It was impossible to miss. A small ant had climbed the wall, ready to carry out its plan—a life-sized ant was a few meters away from me. I’m usually tough, but this time, I panicked and screamed (“Oh my god, an ant!”). “What happened?” my wife was startled. “Since when have you been afraid of insects? Horror boy, are you scared by some little ants that don’t do anything?”.
At this point, I started to stutter. “No, you don’t understand!” I said in a voice that was supposed to be calm but came out shaky. “That ant could be a zombie! Maybe it ate a mushroom in a tropical forest! Then we’ll turn into zombies, too, and the end of humanity will come!”. My wife looked at me with a look that I know so well, the look of “Why the hell did I marry someone who likes horror movies.” I looked back at her apologetically, stammering something about how next time I would watch a romantic comedy with her, and not an apocalyptic zombie horror movie. But before my eyes returned to the TV screen, I glanced at the wall. The ant was gone.
If you’ve seen zombie movies, you probably know that each one has a triggering event that usually explains why the world’s population is in danger: an experiment, a war, a disease, a lousy script, etc. In recent years, mainly thanks to the super-popular TV series “The Last of Us,” we’ve been hearing about another possible cause, at least seemingly: a zombie fungus. This fungus has a scientific basis, which has shown that it can cause this effect mainly in ants, but it’s been enough to create several books, movies, and TV series that present the threat as imaginary.
You are welcome to read about this Zombie Ant Fungus, known as Ophiocordyceps Unilateralis, and understand once again that sometimes nature is the most successful location for horror movies.
What Does Zombie Ant Fungus Do?
You can maybe understand the main characteristics of this insect by its common name, Zombie Ant Fungus“ (no way I’m going to use often the Zombie Ant Fungus scientific name, Ophiocordyceps Unilateralis, more than a few times).
No matter what you call it, it is one of the most fascinating, disturbing, and frightening creatures you will find in nature, one that ignites the imagination of scientists, nature lovers, and, of course, horror fans.
A fungus that exposes us to worlds that seem to be taken from the movies “The Thing” or “Alien, about host-parasite relationships, biology that gets out of control, and the disturbing power of nature. It is a story about a dead ant, after brutally committing suicide, with a fungus growing on its head.
As one might infer from its name and the films that depict it, the zombie fungus’s unique feature is its ability to mind control the behavior of another living creature, which is usually ants (we must note that a picture showing this effect on a fly attracted significant attention in the scientific community). These unfortunate animals become a kind of “zombies,” living under its control and doing precisely what the fungus wants: to die instead of offering conditions for future fungi to continue growing. This phenomenon seems like one from a horror movie, but the truth is that it is the result of millions of years of evolution and mutual adaptation between the fungus and its hosts.
Ophiocordyceps unilateralis is a parasitic fungus that is pathogenic for insects. A British naturalist named Alfred Russel Wallace discovered it back in 1859. Wallace is considered one of the essential names of the theory of evolution, and yet, unlike Charles Darwin, you probably haven’t heard of him. Wallace collected insects and animals on various continents (mainly South America). He discovered, among other things, that a very special plague lived in tropical forests, infecting ants from a tribe called “Camponotini.”
The story of the Zombie Ant Fungus is an example of evolutionary adaptation between a parasite and its host. The zombie fungus is mainly common in tropical and subtropical regions worldwide, such as Southeast Asia, South America, Africa, etc. This is no coincidence. Its geographical distribution is greatly influenced by the presence of the ant species that serve as its hosts. In addition, the conditions in these areas – mainly high humidity, warm temperatures, and dense plant cover, which creates shade and humidity conditions – contribute to its prosperity.
One can claim that fungus plays a vital role in tropical forest ecosystems, helping to regulate ant populations and forming part of the forest’s complex food web. Therefore, possible changes in the fungus population due to global warming or human deforestation could negatively affect the natural balance.
How Does The Zombie Ant Fungus Work?
So, what exactly is happening here? It all starts when the fungus wants to reproduce and sends spores (asexual reproduction and distribution units in plants and fungi) into the air, which is carried by air until they find their “host body.”
When the ant breathes in the spores and takes them into its tiny body, its behavior patterns change. The ant leaves its protected place and sets out on a seemingly routine mission of searching for food in the thick of the forest. The problem is that this is precisely the trap of the zombie fungus. The ant reaches an ideal area for the fungus regarding temperature and humidity, and the magic happens. Or, more precisely, a mass suicide of ants.
So, how does the Zombie Ant Fungus enter the hosts body? In the next step, the ant will attach itself to a central vein at the bottom edge of a leaf using its lower jaw. It will remain there for several days, usually about 4-10, until its death. The next step, ironically, is reproduction, but not what you think. Fruiting bodies grow from the victim’s head and rupture, releasing the fungus’ spores. The spores continue to be distributed even after death, and what’s more, the fungus continues to grow until sexual reproduction. A stalk emerges from the ant’s head with a reddish-brown fruit. To make this happen, the fungus causes a network of cells to form in the ant’s body, cells that eventually unite all of its internal organs and allow for complete control.
What’s strange here is that all this behavior is guided by the fungus itself, meaning that the fungus causes the behavior of the organism that hosts it to change – and in this case, it does what it wants. The fungus essentially “hijacks“ the insect’s nervous system, causing it to climb high and hang upside down on a leaf or stem in ideal conditions until it dies. It controls it even after death.
How Does The Zombie Ant Fungus Begin Its Life Cycle?
In nature, as in nature, this does not happen immediately. The evolutionary process described here took a long time, perhaps even millions of years. In a more specific sense, at present, it usually takes 2-3 weeks after the fungus enters the ant’s body for it to move toward the leaf. From the fungus’s perspective, the fixation of its jaws to the underside of the leaf is the ideal condition for the spread of its spores.
We can summarize the Zombie Ant Fungus life cycle as follows:
🐜 Infection: A spore of the fungus is introduced into the ant’s body
🐜 Penetration: The spore sprouts webs that penetrate the ant’s body
🐜 Spread: The fungus spreads throughout the ant’s body, feeding on its tissues
🐜 Behavioral control: The fungus takes over the ant’s nervous system
🐜 Strategic placement: The ant climbs and clings to a plant at an optimal height for the fungus
🐜 death and spread: The ant dies, and the fungus develops spores to spread over its dead body
Over the years, scientists have tried to understand the physiological process: What does the fungus control, turning the ants into suicidal zombies? The first instinct is the brain, although the conventional wisdom is that it is not involved here. Findings have shown that the fungus does not penetrate the host’s central nervous system. The control may be in the muscles, and the answer may lie in hormones secreted in the insect’s body and traveling to its brain. However, more research is needed to understand what is happening here and why.
Here is a short Zombie Ant Fungus video from the BBC, which describes the horror movie that takes place in nature:
Meet The Fly Slayer
If you thought that only ants can turn into zombies in nature, you should think again. Other species of “zombie fungi“ can affect various insects. For example, another fungus called “Entomophthora muscae” known as “The Fly Slayer.“ Here, too, the fungus takes over the flies and causes them to perform horrific acts on flies or fruit flies. In one of the central studies in the field, researchers placed the fungus spores on fruit so the flies could taste it. Later, they put the flies in a test tube with a toothpick at the bottom and tried to detect behavioral changes.
The study findings showed that in the first few days after eating the infected fruit, there were no behavioral changes in the flies. However, when ingested by the flies’ tissue, the spores developed into structures resembling webs, as in the case of ants. These webs grew around and into the flies’ control centers – the nervous system and brain – and caused them to change their behavior.
After about 4-5 days from the “infection,” the researchers noticed strange behavior in the infected fly, which stopped flying, moved frantically around the toothpick, and climbed to its end. This is when the fly naturally drips a sticky liquid, which causes it to be fixed to the place where it is. The next stage is the erection of the fly’s wings, when it is dead but in a position that anyone encountering it might mistake and think it is still alive.
After death, the process begins that we thought was reserved mainly for horror and science fiction movies: a fungal structure resembling cotton wool bursts from the abdominal cavity as if entering the “creature,” filling its lower body. The tiny protrusions that make up the structure send out spores, which cause the fungus to multiply and pose a risk of infection among other flies.
Can The Zombie Ant Fungus Infect Humans?
This is a million-dollar question for horror fans, partly because it resembles fictional scenarios of zombie epidemics that we have seen in so many books, films, and TV series. So the good news is that for now, you can rest assured. There is no scientific evidence that this fungus can infect or directly affect humans. The fungus focuses on specific hosts, which are much smaller and are probably not adapted to penetrate and multiply inside the human body. We must not forget that the nervous and brain systems in the human body are significantly different from those of ants and insects. Moreover, the human immune system is much more developed and capable of successfully dealing with diverse threats, including various fungi.
The fungus’s specific growth conditions are also unsuitable for conventional human living environments (even if populations live in tropical forests, mainly tribes). The chances that the fungus will evolve to make it dangerous for humans are slim to non-existent from a scientific point of view, and this will probably not happen in the foreseeable future. Some fungal infections affect humans but do not cause dramatic behavioral changes like in tiny insects. Most species of the fungus are specific to the host due to the same evolutionary process, and this host is not a human.
The Zombie Ant Fungus In Culture
However, in several important cultural texts, we can see the scenario in which these fungi cause these terrible human changes, which could start a zombie epidemic that threatens humanity.
The Last Of Us
The clearest example of why zombie fungi have made headlines in recent years is “The Last of Us,” a popular computer game turning into an equally successful television series. The plot here takes place in the post-apocalyptic United States, in an era in which an epidemic caused by the same fungus has caused most of the population to become zombies. It follows Joel (Pedro Pascal, in the series), a survivor who lost his daughter and embarks on a journey with a young girl named Ellie (Bella Ramsey) in search of hope.
The series received excellent reviews and viewership figures. Many consider it one of the most successful and faithful computer game adaptations, and the second season of the TV series is expected to premiere on HBO in April 2025.
The Girl With All The Gifts
In 2014, we got the horror novel “The Girl with All the Gifts“ by British author M.R Carey. The location and time here are different – Britain, three decades after a global pandemic that wiped out most of humanity – but the cause is, you guessed it, a fungal infection originating from the same zombie fungus. The heroine is Melanie, an extraordinary girl imprisoned in a closed military base, tied to a chair during school lessons, and locked in a locked cell the rest of the day. Later, we will understand why and find out whether humanity can survive.
If this story sounds familiar to you, it is no coincidence: in 2016, a British film of the same name was released based on the book, starring Gemma Arterton, Glenn Close, Paddy Considine, and Sennia Nanua as the girl. The film itself is reasonable and does the job, especially when describing the apocalyptic world and its characters (Arterton, as usual, is excellent as the teacher). It’s hard to argue that it’s a classic horror film with too many thrills, which explains why it’s gone under the radar of many horror fans. In my opinion, as an apocalyptic horror drama that combines a coming-of-age story, “The Girl with All the Gifts“ does the job.
The prequel book, “The Boy on the Bridge,“ was released in 2017 and received positive reviews. The book is a prequel, which occurs before the first book’s events. It focuses on a group of soldiers and scientists who try – apparently without significant success – to find a cure that will eliminate the infection. It has not yet been made into a film, but based on the fact that the film “The Girl with All the Gifts“ received rather lukewarm reviews and was not a box office success (it was only released commercially worldwide, not in the United States, and grossed about $4 million) – it is doubtful that this will happen.
In the coming years, we may hear more about the zombie fungus, understand what is happening to it, and see it appear in more cultural texts – because we always have to think about the causes of global zombie epidemics. Hopefully, this process will continue in science fiction films or tropical forests. After all, it doesn’t sound fun to walk around like a sleepwalker in the jungle, climb a leaf, and die there, with mushrooms growing on my head after death.