[ExI] Ant Games

[Stuart LaForge]

Quoting Spike:

>> ...While your idea of using a string to get ants to get rid of wasps is
> very clever, the guy who took the video who is an amateur ant enthusiast
> claims that this is completely an ant construction with no help from him...
> Stuart LaForge
>
> Hmmmm.  I have seen ant bridges in my tragically misspent youth, but they
> were vertical hangers.
>
> If one works thru the mechanics of the thing, to do this without a structure
> would require the ants went from the attachment points in tight formation
> along the eve, clasped paws (or claws or anything they got now) and
> subsequently released their grip on the underside of the eve.  I can't
> imagine ants doing this, or why they would do it.

The why of the matter is a little easier than the how. An unladen  
worker ant has claws that enable it to crawl across the ceiling  
inverted. Notice the ones scurrying around the base of the wasp nest  
in the video thus the scouts being able to discover the wasp nest and  
set down a pheromone trail. The problem is that the fat white wasp  
larvae probably weigh several times what a worker ant does, and tarsal  
claws are not good enough for that, unlike a fly or a gecko's adhesion  
pads.

The how is harder to ascertain. It is because this genus of ant,  
Eciton, is known for building bridges. Normally they build cantilever  
bridges to cross gaps right side up. But in this case, since they are  
inverted, they built a suspension bridge. It is of note that this  
species builds nests out of their own bodies called bivouacs that hang  
from support structures.

https://www.alamy.com/stock-photo/army-ant-bivouac.html

These hanging bivouacs have millions of individuals inside as well as,  
if I recall correctly, the largest queen of any ant species. They can  
get away with that long massive suspension bridge because their bodies  
are much stronger under tension than they are under compression or  
shear.

https://fineartamerica.com/featured/army-ants-building-bivouac-mark-moffett.html?product=duvet-cover-bodies

The Eciton ant colony forms a very smart swarm mind composed of ants  
whose tiny brain are a larger percent of their mass than our brains  
are ours. Each such ant is in dynamic pheromone and touch contact with  
millions of other individuals within the colony. In the case of army  
ants of the genus Eciton, this hive mind is obsessed with efficiency  
as can be demonstrated by this article from PNAS about the  
pattern/algorithm that army ants use to cross gaps.

https://www.pnas.org/content/112/49/15113#ref-1
https://www.quantamagazine.org/the-simple-algorithm-that-ants-use-to-build-bridges-20180226/

In short, if an ant encounters a gap, then it slows down and tries to  
reach across the gap. If the ant slowing down causes another ant to  
crawl atop it, then the ant that gets walked on essentially grabs on  
tight and freezes in place, becoming a girder in the bridge.

> There must be something more going on, for photography has been with us for
> a long time, yet I find no other examples of anything distantly analogous to
> this bridge.

If you look at the bivouac structures in the alamy link, then you will  
see several structures that are somewhat analogous. Also look closely  
at the video. Here is a better quality copy without any annoying music:

https://www.youtube.com/watch?v=bUNKQqCRFuQ

Notice that there are "bridging" workers. Workers who are stationary  
and acting like support cables. If a man-made string was there, there  
would be no need for the ants to bridge, those bridging workers would  
simply use the string to gather the wasp larvae faster, better, and  
cheaper.

> Could it have been assisted by some other agent who then called upon him
> after the ant bridge was in place?

I did notice that the videographer had his Twitter account deleted so  
maybe you are right. It just seems odd that a hoaxster would use such  
a long string when a much shorter one would have sufficed. Whereas  
small living cables of high tensile strength and low shear modulus,  
would likely try that elongated catenary curve so as to minimize  
gravitational shear forces and exploit their tensile strength. My  
guess is that started somewhere near the middle and worked its way  
outward.

Because the guy deleted his Twitter account, I admit it might be a  
hoax. He is an electrical engineer after all. But there is sufficient  
physical evidence to give it the benefit of the doubt, don't you think?

Stuart LaForge