Zombie Fungus

The security connection is pretty tenuous, so I figured I’d blog this on a Saturday.

Once it infects an ant, the fungus uses as-yet-unidentified chemicals to control the ant’s behavior, Hughes told LiveScience. It directs the ant to leave its colony (a very un-ant-like thing to do) and bite down on the underside of a leaf — the ant’s soon-to-be resting place. Once it is killed by the fungus, the ant remains anchored in place, thanks to its death grip on the leaf.

Ultimately, the fungus produces a long stalk that protrudes from the ant’s head, shooting spores out in the hopes of infecting other ants. Two of the four newly discovered species also sprouted smaller stalks elsewhere, including from the victim’s feet and lower leg joints – the equivalent of knees.

Posted on March 19, 2011 at 9:12 AM57 Comments


Craig March 19, 2011 9:26 AM

Now that the fungus has experimentally demonstrated the feasibility of this project, all that remains is to scale it up to work on humans. Then we will be able to eliminate terrorism and thoughtcrime and inaugurate a millennium of peace and harmony!

JHD March 19, 2011 9:53 AM

Well, this suggests a type of explanation for the US presence in Iraq, Afghanistan, and the vast military base system.

I have long suspected we are ruled by fungi.

Nick P March 19, 2011 1:31 PM

Two thoughts. The zombie fungus is yet another indicator that the scenario on the movie The Happening is plausible. Another thought came to mind when reading the entry on Toxoplasma gondii. I couldn’t help but notice how similar the symptoms were to the core symptoms of Aspergers Syndrome, which is growing stateside. I’ve also seen surveys that indicate most people with Aspergers prefer cats. There might be a connection, there.

Although, all the evidence seems to indicate it being a genetic condition. I guess I’m wondering if a percentage of people with Aspergers and similar conditions are misdiagnosed cases of toxoplasmosis.

Shane March 19, 2011 1:39 PM

To augment kbob and Nick P, I present a very interesting talk by Robert Sapolsky about toxoplasma gondii.


Synopsis: It grows inside a cat and propagates via cat poop, which is eaten by a mouse, which then goes out of its way to get back inside a cat. In humans, toxo is linked to dangerous behavior (excessive speeding, motorcycles) and schizophrenia.

To bring us back to security, he also says that the US military is “intrigued” by these effects. Indeed…

Mike C March 19, 2011 1:48 PM

I’ve heard about this fungus. What the article doesn’t mention is that the fungus makes the ant climb up high before it bites into the leaf (thus increasing the dispersal area of the spores), and that other ants will go out of their way to move an infected ant away from the colony. Both of these observations have a bit more of a security implication.

Nick P March 19, 2011 2:43 PM

@ Mike C

That’s neat. There is definitely a security implication there: the hive is acting analagously to an immune system, detecting the infection and trying to remove it.

@ Shane

Thanks for the link. It certainly didn’t calm my worries. 🙁

LWR March 19, 2011 3:43 PM

I’ll have to work a weaponized version of this into my entry for your next Movie Plot Threat contest…

Clive Robinson March 19, 2011 4:39 PM

This “zombie behaviour” also occurs in the common garden snail.

It is caused by what would commonly be considered a parasite “Leucochloridium paradoxum” or more commonly “the green-banded broodsac” (I’ve mentioned it here before back on 2 July 09).

Technicaly it’s not a parasite when in the snail because it kills the host as part of it’s breeding cycle, which is like the tapeworm and other flatworms is via a couple of hosts. As in most two host flatworm life cycles one of the hosts is an intermediate or sacrificial host (the snail in this case the pig in the common tenia case). The adult stage or definitive host in this case is a bird where the Leucochloridium paradoxum reproduces sexually and produces eggs that excreated along with other diatry waste.

So far so boring…

The interesting thing is what happens to the sacrificial host or the snail…

The garden snail ingests the worm in its miracidia stage, where once in the digestive system of the snail it moves out of the digestive tract into the live flesh of the snail as it develops into the sporocyst stage.

The sporocyst grows into long tube and seeks out the snails optic nerve which it grows along into the left eye stalk (if the snail has one). In the process it “zombifies” or in computer security terms “ownes” the snail, and significantly changes it’s behaviour.

An “unowned” snail is usually light averse and remains in the undergrowth during the day usually only comming out to feed in the open at night. The mature sporocyst reverses this behaviour and the snail climbes up towwards the light where it becomes easily visable to birds.

In it’s mature form the sporocyst forms as a swollen”broodsac” filled with upto hundreds of cercariae. The tip in the snails eye stalk transforms the stalk from it’s usual slender dark greyish brown form to a bright green swollan pulsating form looking like a large fat caterpillar or other similar grub.

It appears that the pulsating is in response to light as it virtualy stops in low light levels and to a certain extent the snails behaviour reverts to it’s normal expected activities.

Now the gruesome bit, in bright light the snail climbs to the top of a stlak of grass or leaf etc and extends the eye stalk. A bird seeing the pulsating sporocyst grabs it in it’s beak and flys off with it. Sometimes the snail goes with it on other occasions the sporocyst is draged out of it’s flesh…

Some people belive that this draging out of the sporocyst may not always be fatal to the snail as there are more snails found with missing left eye stalks than right…

Oh and the snails that get infected by the worm are the same as the ones the French Italians and other sothern Europeans eat…

tommy March 19, 2011 5:41 PM

No confidence, Bruce? The security analogy is obvious. Virus (fungus) infects computer, disables AV (gets ant to leave colony), disguises itself (hide under leaf), and replicates, sends itself to everyone in your e-mail list, etc. (“Ultimately, the fungus produces a long stalk that protrudes from the ant’s head, shooting spores out in the hopes of infecting other ants.”)

Quick and easy parallel to any security threat invading a host, disabling defenses, making detection difficult, and attempting to invade others, either actively or by passive attraction. Q. E. D.

Debianero March 19, 2011 7:24 PM

Spatterjay virus is here!

P.S. If you don’t understand the joke, look for Neal Asher.

Clive Robinson March 19, 2011 8:49 PM

Off Topic.

RSA confirms that technical information on it’s two factor security tokens etc has been targeted by attackers, apparently successfully,


Although RSA put this down as an APT attack it is in reality an “upstream supply chain” attack.

We tend to buy technology on trust as we have no way to check it, so rather than attack us directly some people have started to attack our supply chains as this is more productive.

This is not the first time this has happened. If people think back Apple had problems when an employee of an outsourced part of their business put malware onto Apple branded products.

Likewise EPOS terminals destined for the UK were reputed to have had miniture cellular phones put in them to send of card holder details and PIN info.

I fully expect to see more of this kind of attack. And as RobertT has pointed out there is little or nothing stoping a skilled attacker actually going after the silicon that goes in consumer products such as comms and CPU chips that are destined for Smart Phones etc.

Nick P March 19, 2011 11:18 PM

@ Shane

The organism basically makes people and rodents do stupid things that can get us killed. The article mentions military is researching this stuff. So, the military wants to hit our enemies with a compound that makes them act in a dangerous, impulsive and aggressive way? Like we use it in Iraq, then a bunch of insurgents strap bombs to their chests and drive into our checkpoints? Wait a sec, maybe it was weaponized and worked TOO well. 😉

Steven Clark March 19, 2011 11:29 PM

This particular beastie, and a whole host of similarly creative parasites, have been amusing biologists for quite a while now.

Reality, for scientists, is at least as interesting as fiction: and often a darn sight scarier/weirder/stranger 😀

“Anything you can do, we can do better!”

Brett March 20, 2011 2:38 AM

I recall reading about this within the past month, and also some time more than a year ago. For a competent source, I found this paper on the phenomenon in the (online) American Naturalist Vol. 174, No. 3, September 2009: http://www.jstor.org/pss/10.1086/603640.

It models an unwitting accomplice


Clive Robinson March 20, 2011 5:45 AM

@ Brett,

Your link does not appear to point to a valid resourse on Jstor as the “were sorry” page comes up.

Do you have the author and title of the paper etc so it can be googled?

Roger March 20, 2011 9:25 AM

Ah, Nature in all its glory!

On the subject of infections that modify the hosts’ behaviour, Yersinia pestis (black death bacterium) modifies the behaviour of fleas to enhance its transmission. It secrets a protein which blocks the flea’s gut, causing it starve, so it moves rapidly from host to host, biting franticly. At each host it tries to swallow blood which won’t fit in the gut, so the flea vomits back up the victim’s blood mixed with a biofilm of bacteria, right into the open wound of the bite. Of course the flea dies from starvation.

And in a sense, even the coughs and sneezes of respiratory infections fall into this class.

However Clive, I think your worms have just replaced the ichneumon fly as my standard example to use on people who equate “natural” with “nice”.

Clive Robinson March 20, 2011 1:43 PM

@ Roger,

“And in a sense, even the coughs and sneezes of respiratory infections fall into this class”

If you think about it many viral infections in the early stages cause humans to have “chills” that make us think we are cold and thus seek out warmth. In times past that would have been the body heat of others, thus causing the infection to spread to them.

It makes you wonder if “man in all his glory” could in reality become “owned” or “zombified” by some pathogen…

After all there are enough examples floating around to show it’s possible, and further it is easy to believe that as with your “black death” bacteria we may well have missed seeing some more subtal vectors of control.

So it is going to be very difficult to say “zombification” in humans cann’t happen.

I guess the next question that arises is why has it not yet happened?

Or has it happened in the past but something in our behavior has caused it to die out.

For instance there is very little in our behaviour to stop us being hosts to various round and flatworms, yet we are not currently the sacrificial intermediate host. Nearly all our livestock however can be or are sacrificial hosts, where the early stage eggs are eaten from grass etc infected by the dropping of human waste.

In nearly all cases the sacrificial or intermediate host has it’s behaviour changed in some way such that it is significantly more likley to die by predation. And in consiquence the cysts within it’s flesh or organs get consumed by the second or definative host where the worm can live for upto twenty or thirty years in it’s dietary tract…

Could it be that our “death rituals” have in the past broken the chain and such that any parasite of that form using us as the sacrifical or intermediate host has quite literaly died out because other animals nolonger eat our raw flesh either fresh or as carrion?

Is there a parallel in information security to “death rituals” that would be useful to consider…

Either way the definately food for thought so as the French say “bon appétit”

Thomas March 20, 2011 4:03 PM

“””Is there a parallel in information security to “death rituals” that would be useful to consider…”””

Cremating old PCs? Sending them out to sea in a burning barge? Extracting still-running CPU’s to appease the Gods?

What about “life rituals”, like monogamy (one PC, one user)?

tommy March 20, 2011 4:25 PM

@ GirlBogs, it is not possible to be “interested” in the discussions here and also be a strong FB fan. The two are mutually exclusive.

Also, one would think that FB gets enough free publicity from the general media without you having to link it twice in one post (your sig). It wasn’t even your own personal FB page, just the home page, for SEO? ‘Bye.

Some of us link our sigs to our own pages or to other stuff that we hope the crowd here might find interesting/amusing, etc. (FBspam? Sheesh!)

sbi March 20, 2011 4:52 PM

I read a similar story once abut that parasite living in ants and sheep (sorry, but I don’t know the English terms enough to be more specific), which manipulates ants to climb to the top of a grass stem and cling there, to be eaten by the sheep, to which the parasite then transfers.

Davi Ottenheimer March 20, 2011 4:55 PM

I always wonder if the “climb to the top” mechanism is actually a “towards the light” or an “away from heat” reaction. Can a fungus direct up/down or is it another trigger?

Dirk Praet March 20, 2011 5:15 PM

I bet some folks in Langley must be absolutely thrilled with this discovery. Except perhaps for some lone guy in the basement wondering how his science project got out of the lab.

Ick March 20, 2011 8:17 PM

Love your blog and books. I saw this on several sites. All with high ick factor.

None had a Langley emplies wondering how it escaped the lab.

Double ick.

Of course there is a similarity to buying books from Bruce. Don’t think. See. Buy.

How did you infect us. And with what?


Andrew_M_Garland March 20, 2011 11:03 PM

Future News:

Researchers within both the Democratic and Republican parties are working hard to determine if the behavior of the other party can be linked to the operation of a human analogue of the “zombie fungus”.

A positive result would be both a satisfying scientific achievement and a potent campaign slogan.

AC2 March 21, 2011 12:17 AM


That was just gross… Never have and never will touch or eat a snail…

Wonder if anyone will tell Spongebob???

I never liked cats anyway, but next thing you know this toxoplasma shit will have worked its way into your favourite law & order soap, where the defence lawyer pulls it out of the bag to get his wretched client off…

Derryl March 21, 2011 2:32 AM

I can see it now… “Mysterious Spores Sprout From Heads and Knees of Taliban Operatives, JSOC Implicated in Cover-Up”

Winter March 21, 2011 3:34 AM

Stories like these make biologists averse of believing in some benevolent creator. Anything that thought out this (and parasitic wasps) is not something you want to believe in if you can help it.

Clive Robinson March 21, 2011 4:27 AM

@ AC2,

“but next thing you know this toxoplasma shit will have worked its way into your favourite law & order soap”

How about Movie Villains such as 007 and Ernst Blowefeld (or however you spell his name 8) and that darn white hissy fit furball with the diamond collar?

@ Thomas,

With regards “death rituals” I was thinking a little more finaly grained like sanitization between reboots from known safe media with a souped up version of tripewire etc.

(@ All)

However did you read one of the attached articles and notice that David Hughes description of the uninfected “carpenter ants” in that they try to live above the fungus’s prefered “micro climate” and also avoid areas where an ant has died from it?

This sounds like primative sanitation / death rituals… Maybe collectively some species of ants are a bit smarter than we give them credit for…

Afterall one definition of intelligence is “the ability to patern match, record and communicate information” which is one way these rituals arise.

The question is if it is by simple evolution, or directed by the ants themselves in some way?

If it’s the latter then answering the question of “how” maybe way more important in the long run than answering “how the fungus controls the ant”…

Winter March 21, 2011 7:39 AM

@Clive Robinson
“Maybe collectively some species of ants are a bit smarter than we give them credit for…”

You have obviously not followed the field 😉

Boris Ryabko and Zhanna Reznikova. The Use of Ideas of Information Theory for Studying “Language” and Intelligence in Ants.
Entropy 2009, 11(4), 836-853;


This approach enabled us to obtain the following important
results on ants’ communication and intelligence: (i) to reveal “distant homing” in ants,
that is, their ability to transfer information about remote events; (ii) to estimate the rate of
information transmission; (iii) to reveal that ants are able to grasp regularities and to use them
for “compression” of information; (iv) to reveal that ants are able to transfer to each other
the information about the number of objects; (v) to discover that ants can add and subtract
small numbers.

Bryan Feir March 21, 2011 10:15 AM

@Steven Clark:
“Reality, for scientists, is at least as interesting as fiction: and often a darn sight scarier/weirder/stranger.”

Of course truth is stranger than fiction. Fiction has to make sense!

Matt March 21, 2011 10:40 AM

@ Winter
“Stories like these make biologists averse of believing in some benevolent creator. Anything that thought out this (and parasitic wasps) is not something you want to believe in if you can help it.”

Yet stories like these make evolution less plausible.

Winter March 21, 2011 12:51 PM


This is introductory level stuff in evolutionary population genetics. It is fairly easy to work it into a quantitative homework assignment starting from a fungus occasionally excreting a neurotoxin that affects phototaxis..

Tim! March 21, 2011 3:22 PM

“Yet stories like these make evolution less plausible.”

Comments like these make ignorance of the theoretical mechanisms, capabilities, and timeframe of evolution more obvious.

tb March 22, 2011 8:22 AM

They had video of this in an episode of Planet Earth from BBC in 2006 (I believe it was episode 8, “Jungles”). The series was later repackaged with a different narrator on the Discovery channel in the US.

Nate March 24, 2011 11:38 AM

As has been stated previously, I believe it was the members of the colony that moved the infected ant AWAY from the colony to prevent further infection.

And this definitely was covered in “Planet Earth” which is an amazing series that I highly recommend to all who haven’t seen it.

wrm April 15, 2011 4:00 AM

I read a similar story once abut that
parasite living in ants and sheep

Yea, I was also reminded of this. Lyall Watson wrote about it, so it’s not exactly news… but the world is a more interesting place than most of us know.

chappo007 May 4, 2011 6:26 AM

Hasn’t anyone ever seen leeches grappling out from trees and bushes looking for a passing victim. They get out on the very tips of leaves and spikes and then stretch right out feeling, probably tasting the air for a passer-by.

The behaviour of anything that is a symbiant requires it to have an adaptive behaviour – that’s Darwinism. Although leeches aren’t really symbiant to humans.

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