The Zombie Ant Fungus - Botanical Mind-Control

Mind-control fungi - not just a sci-fi/fantasy trope! The Cordyceps group* are some of the most bizarre parasites I've ever personally encountered. Living throughout much of the world (but especially the humid tropics), these fungi lie in wait to infect and slowly take over the bodies of unsuspecting insects and use them for their own ends. The stuff of nightmares if you're an ant capable of dreaming and abstract thinking (and apparently also if you watched/played The Last of Us), but also a fascinating look into the staggering complexity that hides within the tiny details of the forest here in Costa Rica.
*Note: here I'm referring to fungi from several genuses within several different families, especially the genuses Cordyceps, Ophiocordyceps, and a few others which share a similar method of reproduction through parasitism.
Fungi in this video:
Zombie Ant Fungus (species uncertain, possibly Ophiocordyceps unilateralis)
Ophiocordycipitaceae family
Image Credits:
Fungi:
Leila Dasher, iNaturalist, Creative Commons Attribution 4.0
Eugene Popov, iNaturalist, Creative Commons Attribution 4.0
Jonghyun Park (2), iNaturalist, Creative Commons Attribution 4.0
Katja Schulz (2), iNaturalist, Creative Commons Attribution 4.0
Ants:
Katja Schulz (6), iNaturalist, Creative Commons Attribution 4.0
Judy Gallagher (3), flickr.com, Creative Commons Attribution 2.0
Yeast: Alexander Klepnev, Wikimedia Commons, Creative Commons Attribution 4.0 International
Filmed at and around Tamandua Biological Station, close to Corcovado National Park (Osa Peninsula).
Special thanks to Rebeca Quirós and Allan Montes.
Instagram: @amblingwithsam

[@Pho7on]

Great video as usual!

[@DarrenEnns1]

So cool that you found this! Over the past year or so I have watched videos on this weird stuff :)

[@ThisIsSamsWife]

I wish I would have caught his reaction on camera when he first found this ant. I think that’s the most excited I’ve ever seen him before. I couldn’t even come close to touching the other side of the leaf before his inner mother hen came out and he would move it for me 😂😂 Great video love! ❤

[@padego58]

I wasn't really wanting to start my Saturday morning with nightmare fuel but here we are....

[@BeCreative]

how does the fungus tell the ant it wants to grow upside down without a brain? turn the car around sam, i'm getting afraid. i don't want to amble here with you.

[@AmblingwithSam]

Yeah, my wife got pretty freaked out by it too. She's the reason I thought to add the part about it not affecting humans, haha. Rest assured the car is turning around! The next videos will be a lot more pleasant. About how it communicates that to the ant, there's a lot that's still unclear. This paper gives an in-depth overview of current research and ideas on how these sorts of fungi affect their hosts. www.ncbi.nlm.nih.gov/pmc/articles/PMC8546595/ The study is quite technical, and kind of graphic to imagine certain parts, but it seems to be a complex mix of the fungus manipulating muscle tissues, and releasing chemicals that affect parts of the insects' brains and nervous systems in a myriad of different ways. Some of these that could play into going to the underside of a leaf would be where the ant already has pathways in its brain for moving in response to environmental conditions such as light, gravity, and temperature, which would come ordinarily into play when it climbs up and down from its home in the canopy. So if the fungus sends out chemicals that manipulate those pathways, in the case of the ant going for the underside of a leaf, it could just be a matter of sending signals so that the ant is going, "I need to go somewhere brighter/higher/warmer" until it ends up on the underside of a leaf, which matches the light/heat conditions it's craving (which will have different light conditions than the top of a leaf, and perhaps the gravity sense could connect with it wanting to be upside down). Part of this is my own speculation and simplifying based on the information in that study, but it's a fascinating topic!