Termite mounds. They may look like just a big pile of well-structured dirt but they are actually marvels of architecture and fill an unexpectedly important function in the ecosystems in which they appear. In fact, the areas around termite mounds can be some of the most biologically diverse in an entire habitat.
From the functions they serve for termites to the functions they serve for other animal and plant life, termite mounds are mind-blowing!
Heating, Cooling, Homes and Fortresses
First, let's address the structure of these things. Mound-building termites live in Africa, Australia and South America and the mounds they create are enormous -- as big as 30 meters in diameter. I mean really, look at the size of these things -- here's one with a human nearby for comparison:
And they are extremely complex in their architecture. From Wikipedia:
Inside the mound is an extensive system of tunnels and conduits that serves as a ventilation system for the underground nest. In order to get good ventilation, the termites will construct several shafts leading down to the cellar located beneath the nest. The mound is built above the subterranean nest. The nest itself is a spheroidal structure consisting of numerous gallery chambers. They come in a wide variety of shapes and sizes. Some, like Odontotermes termites build open chimneys or vent holes into their mounds, while others build completely enclosed mounds like Macrotermes. The Amitermes (Magnetic termites) mounds are created tall, thin, wedge-shaped, usually oriented north-south.
And from the legend himself, Sir David Attenborough:
So for termites, they are home, kitchen, nursery, fortress against enemies, and they're are built with heating and cooling systems in place. In fact, the heating and cooling capabilities alone are pretty mind-blowing.
From PBS Nature:
A city of termites requires a lot of food, and the mound has many storage chambers for wood, the insect’s primary food source. Termites also cultivate fungal gardens, located inside the main nest area. Termites eat this fungus which helps them extract nutrients from the wood they consume. Maintaining the fungal gardens takes precise temperature control, and the remarkable architecture of the mound keeps the temperature almost constant.
But these mounds serve a much greater purpose than those benefits the termites receive.
As you've noticed, these mounds help other animals overcome the problem of seeing far in the distance in a very flat grassland.
They help other animals reach food sources.
Or they are the food source.
The mounds are so well-built they outlast the colony itself, which means the mounds are fair game to become home to new termite colonies or other wildlife.
And importantly, the mounds help to create biologically diverse habitat that helps the survival of many, many species. When ants attack and many ants and termites die in their battles, the bodies provide nutrients for the soil around the mounds. In addition, the feces and food scraps of those animals that use the mounds as lookouts also add to building up nutrients in the surrounding soil. Additionally, the way termites build the mounds plays a role in helping the soil absorb rainwater. From World Environment:
[Scientists] found that each mound supports a dense aggregation of flora and fauna which grows more rapidly the closer to the mound it is. Conversely, animal population and reproductively noticeably declined at greater distances from the mound. One of the primary causes of this phenomenon is believed to be the actual construction and maintenance of the termite mounds. The workers bring up relatively coarse particles to be deposited on the otherwise fine soil. The coarser particles aid in the absorption of rainwater into the soil and discourage movement of topsoil in response to precipitation and drought. The mounds also contain a high level of nitrogen and phosphorous, nutrients that enhance plant growth.
All this allows plant life to flourish and attracts animals. The cycle continues, and revolves around these castles of dirt and termite spit. They are of great value even as they erode over decades or even centuries into small hills.
So the next time you're out wandering around and come across some strange dirt cathedral, pause and appreciate that it is so, so much more than oddly-shaped dirt, or a home for bugs. It is a wonder of nature. Stop, stare, and let your mind blow up.