November 22, 2024

Mechanisms of Mind Control: Brain-Altering Parasite Turns Ants Into Zombies at Dawn and Dusk

Dissected ant and where you can see the encapsulated parasites (white oval structures) spilling out of the hind body. Credit: Brian Lund Fredensborg
It takes control of the brains of ants, triggering them to cling to blades of grass against their will. The lancet liver fluke has a remarkable lifecycle method, in which snails, ants, and grazing animals are unwitting actors. Scientists are now investigating the accurate systems behind this intriguing type of mind control.
Think of coming to, jaws grasping the top of a swaying blade of grass, unaware of how you got there. Thats the truth for ants contaminated with the lancet liver fluke, a tiny parasitic flatworm. Liver flukes have a complicated, nearly remarkably conceived life cycle, which starts with the hijacking of the ants brain. The unsuspecting ant climbs and secures its effective jaws onto the top of a blade of grass, making it more likely to be eaten by grazers such as deer and cattle.
Researchers from the University of Copenhagens Department of Plant and Environmental Sciences have actually found that the parasites capability to manage the ant is even more shrewd than previously thought. Impressively, the parasite can even get the ant to crawl pull back the blade of grass when it gets too hot.

The unwary ant climbs up and clamps its effective jaws onto the top of a blade of yard, making it most likely to be eaten by grazers such as deer and livestock. Credit: University of Copenhagen
” Getting the ants high up in the yard for when deer or livestock graze during the cool morning and evening hours, and then down once again to prevent the suns lethal rays, is quite wise. Our discovery reveals a parasite that is more advanced than we originally believed it to be,” describes Associate Professor Brian Lund Fredensborg, who carried out the research study together with former college student Simone Nordstrand Gasque, now a PhD trainee at Wageningen University in the Netherlands.
The research study of the parasite has just been released in the clinical journal Behavioral Ecology.
Zombie “On/Off Switch”
The researchers tagged a number of hundred contaminated ants in the Bidstrup Forests near Roskilde, Denmark.
” It took some mastery to glue colors and numbers onto the rear sectors of the ants, but it allowed us to keep an eye on them for longer amount of times,” says Brian Lund Fredensborg.
The researchers tagged a number of hundred contaminated ants in the Bidstrup Forests near Roskilde, Denmark. Credit: University of Copenhagen
When the temperature was low, the ants were more most likely to be attached to the top of a blade of turf. When the temperature increased, the ants gave up the yard and crawled back down.
” We discovered a clear correlation between temperature level and ant behavior. We joked about having actually found the ants zombie switch,” says Brian Lund Fredensborg.
Trojan Horse
As soon as the liver fluke infects the ant, a number of hundred parasites attack the ants body. Only one makes its method to the brain, where it can affect the ants habits. The rest of the liver flukes hide themselves in the ants abdomen.
” Here, there can be hundreds of liver flukes waiting on the ant to get them into their next host. They are covered in a capsule which protects them from the following hosts stomach acid, while the liver fluke that took control of the ant, passes away. You could say that it sacrifices itself for the others,” explains Brian Lund Fredensborg.
Animals contaminated with numerous liver flukes can suffer liver damage as the parasite walks around the hosts liver and bile ducts.
Associate Professor Brian Lund Fredensborg. Credit: University of Copenhagen
Natures Biggest Influencer
Brian Lund Fredensborg notes that there are many other examples of parasites that change animal habits. As such, parasites that pirate their hosts behavior have a higher hand in the food cycle than lots of might believe. According to Fredensborg, this new study sheds light on an exceptionally underrated group of creatures.
” Historically, parasites have never actually been focused on that much, despite there being scientific sources that say that parasitism is the most extensive life type. The hidden world of parasites forms a considerable part of biodiversity, and by altering the hosts habits, they can help determine who eats what in nature.
The tiny liver fluke is widespread in Denmark and other temperate regions worldwide. The scientist and his colleagues will continue to examine the parasite, and exactly how it takes control of an ants brain.
” We now know that temperature figures out when the parasite will take control of an ants brain. However we still require to figure out which mixed drink of chemical substances the parasite uses to turn ants into zombies,” Fredensborg concludes.

Box: Liver Fluke Life Cycle

Reference: “Expression of trematode-induced zombie-ant habits is highly connected with temperature” by Simone Nordstrand Gasque and Brian Lund Fredensborg, 24 August 2023, Behavioral Ecology.DOI: 10.1093/ beheco/arad064.

The zombie ant: The liver fluke infects an ants brain causing it to secure onto a blade of lawn so that its next host– a cow, sheep, deer or other grazer– eats it. A large flock of flukes waits for transmission in the ants abdomen.
The grazer: Once the grazer consumes a contaminated ant, it becomes contaminated with the liver fluke. The liver fluke that took control of the ants brain dies in the hosts stomach acid. When in the hosts intestine, the larger flock in the ants abdomen is safeguarded by a capsule that just liquifies. Here, the liver flukes find their method through the bile ducts into the liver, where they suck blood and become adult flukes that begin to lay eggs, which are then excreted through the host animals feces.
The snail: Once the fluke eggs have actually been excreted, they rest on the ground awaiting a snail to crawl by and take in the feces. Within the snail, the eggs turn into larval flukes that recreate asexually, where they can increase into several thousand.
The slime ball: To exit the snail and move on to its next host, the larval flukes cause the snail to cough, thereby expelling it in a lump of mucus. Ants are attracted to the ball of mucus and consume it, and in doing so, ingest the fluke larvae.

Liver flukes have a complicated, almost remarkably developed life cycle, which starts with the hijacking of the ants brain. As soon as the liver fluke infects the ant, numerous hundred parasites get into the ants body.” Here, there can be hundreds of liver flukes waiting for the ant to get them into their next host. They are covered in a capsule which secures them from the ensuing hosts stomach acid, while the liver fluke that took control of the ant, dies. The liver fluke that took control of the ants brain passes away in the hosts stomach acid.