A Metropolis of 200 Million Termite Mounds Was Hidden in Plain Sight

November 20, 2018 11:57 AM

Termite mounds that are still in use despite being almost 4,000 years old are spread over an area the size of Britain in a remote Brazilian forest. In the course of digging tunnels over thousands of years, "the termites moved more than 10 cubic kilometers (that’s more than 2.6 trillion U.S. gallons) of earth," and the entomologists investigating them took soil samples that "indicated mound fill dates between 690 to 3820 years ago."
posted by mandolin conspiracy (13 comments total)

Wow.

For perspective, the Great Pyramid of Giza occupies a bit more than 90,000 cubic feet, or 700,000 gallons, or 0.003 cubic kilometers. The volume of earth moved by these termites is thus roughly the equivalent of four thousand Great Pyramids, or an average of about one per year since the colony was started.

This would be an amazing feat for humans, but given the relative size of the termites, it’s astounding.
posted by darkstar at 12:17 PM on November 20, 2018 [4 favorites]

*coughs*
posted by Fizz at 12:32 PM on November 20, 2018 [9 favorites]

Further convincing me that insects just tolerate us and we should be wary indeed.
posted by RolandOfEld at 12:33 PM on November 20, 2018

i support these dedicated and organized laborers of the working class
posted by poffin boffin at 12:39 PM on November 20, 2018 [5 favorites]

It's as if nothing infests their homes and eats them from the inside out.
posted by srboisvert at 12:41 PM on November 20, 2018 [1 favorite]

Should probably stop pouring molten metal into their homes to make destructive castings.
posted by ZeusHumms at 12:43 PM on November 20, 2018 [1 favorite]

Found 'em!
posted by HumanComplex at 12:53 PM on November 20, 2018 [5 favorites]

More on termite nest casting. It's a sort of horrifying process if you think of it from the insects' point of views, but the resulting casts are amazing.
posted by Nelson at 1:47 PM on November 20, 2018 [1 favorite]

From the OP's linked article Current Biology — A vast 4,000-year-old spatial pattern of termite mounds:

The mounds are not nests, but rather they are generated by the excavation of vast inter-connecting tunnel networks [high-res image of Figure 1], resulting in approximately 10 km3 of soil being deposited in 200 million conical mounds that are 2.5 m tall and approximately 9 m in diameter.

...each mound is simply an amorphous mass of soil without any internal structure. Newly forming mounds contain a single large (diameter of ∼10 cm) central tunnel descending into the ground that intersects with an extensive network of underground tunnels (diameter of up to 10 cm) and narrow horizontal galleries containing harvested discs of dead leaves or brood...

...to date, no royal chamber has been located either in or below a mound, despite extensive searching. The tunnels are never left open to the environment, ruling out their use as a ventilation system [6].

At night, when food is available, groups of 10–50 workers and soldiers emerge onto the forest floor between the mounds from an array of small (diameter of ∼8 mm) temporary tubes excavated from below; those temporary tubes are sealed shut after use.

On the low end (assuming 10 workers/soldiers emerge between ~200,000,000 mounds), there could be billions of tiny troglodytes foraging for food every night. This gives a whole new meaning to "Honey, could you stop at the store on your way home?"

More about Syntermes dirus termites in The Biology of Nine Termite Species (Isoptera: Termitidae) From the Cerrado of Central Brazil [PDF - HR Coles de Negrit & KH Redford, 1982].
posted by cenoxo at 3:20 PM on November 20, 2018 [5 favorites]

what are they eating and how is there so much of it to support such a large area? my nightmares will be filled of what would happen if this termite colony collapsed and all that food didn't get eaten.
posted by evening at 5:44 PM on November 20, 2018

The Green Brain by Frank Herbert has something to say about insects: Green Brain
posted by MovableBookLady at 10:07 PM on November 20, 2018 [1 favorite]

Herbert really had a thing about insects, didn't he? (see also Hellstrom's Hive and, metaphorically, Dune)
posted by kokaku at 2:27 AM on November 21, 2018

See also Brian Aldiss' Hothouse.

It's all very impressive,but also weirdly mundane. A well-suited species in a stable niche has no particular end point, and over time the humbers of whatever it is they do will stack up. Termites excite us because they build mounds and thus are very alien beings that lend themselves to anthropomorphosis. Cities, air-conditioning, metropolis... (hell, queens, soldiers and workers...). I forget what the numbers are for topsoil processing through the guts of earthworms, and have no idea how long they've been doing it as a species, but I bet the headline figures make the termites look like a toddler on a beach making a castle with a yoghurt put.

(Oh, OK then. An acre of English farmland can have a million worms, which process around 320 kilos of soil in a day. In 5000 years that's 575 million kilos. Per acre. There are 42 million acres of arable land in the UK ('an area the size of Britain'). At 1600 kg per cubic metre, that all works out to 1.509375e+13 cubic metres or 15 cubic kilometres. Spin on it, termies)

Call me when they invent temples and brewing.
posted by Devonian at 3:08 PM on November 21, 2018