Sorry for the late reply, was a busy day.
Had a better look at the mounds and deduced that it is infact a mound of
Trinervitermes. Which is in the same subfamily as the Amitermes just the size of the holes in the mound made me rethink slightly. They both exhibit blackened mounds and soldiers are characterized by a snouted long pointy conical head capsule which secretes a deterrent fluid upon harassment. Which groups both in the subfamily Nasutitermitinae (if you care)…
Right so the mounds are made from digested paste as I mentioned earlier. The Trinervitermes are unlike the Macrotermes [ which i mentioned in another thread about who is responsible for the large termite hueweltjies/towers found in kruger] as they do not require to cultivate fungus to break down their cellulose rich plant material diets like the macrotermes.
They contain enzymes within their hindgut and saliva which enable the breakdown of cellulose. This is a direct resilt as being in a symbiosis with unicellular eukaryotic flagellates often making up 1/3 of the termites mass. These gut flaggelates are often colonized by prokaryotic bacteria.
Endomicrobia are a lineage of bacterial microbes which is present in, and often
restricted to hind guts of certain termites and wood-eating cockroaches. These bacteria (often referred to as TG-1 [termite group 1] bacteria) are capable of cellulase production and therefore cellulose digestion.
The particular termite species happens to do all this with dark pigmented chemicals persisting to the digested material 'waste' which gives its saliva, and therefore mound (and old queen) its colour.
Now queens are housed in elaborate chambers underneath such visable mounds to offer a certain degree of protection. These colonies grow very slowly and take about a decade to reach maturity. Like an ice-berg 95% of the mound is under the surface. Making digging to get there quite an incentive.
Predators such as aardvark are specialized to get past such protection as they are increadibly capable earth moving machines and have evolved for just such porposes. They dig into the mound and have a feast.
The holes are as ecologically important as the mounds themselves as many species use them for shelter. As I mentioned above Warthogs can dig, but are lazy creatures and would rather modify existing aardvark burrows. Few African species are as diurnal (strictly daytime) as the warthog. This is useful as Porcupines are nocturnal and use such holes during the day for shelter and sleep. When the warthog gets up in the morning to start a day and leaves the den, the porcupine is just coming home. When the warthog comes to sleep, the porcupine goes out foraging.
This is a great setup, except warthog have tusks on the front. So for protection they backup down the hole ready to fend off trespassers with their only weapons. Porcupines on the otherhand have spines on their backs. So they move down head first leaving the most protected rear wall of spines facing outwards to fend off intruders.
I have more than once seen warthog with quills stickin in their porcine posteriors for coming home early, backing up down their hole and not seeing the porcupine still sleeping in the hole. Recipe for disaster

prick in the bum and an uncomfortable few days for the warthog.
AWD's do not dig their own dens. Which results in aardvark burrows playing a very active role in their conservation, as AWD need dens to litter pups. Spotted hyena often utilize such dens as do ground squirrels and serval.
Sorry if I went into
too much detail I just have the pleasure of working with probably the top entomologist in South Africa. Who recently (2002) played a huge part in describing the new insect order mantophasmatodea, the first new order since ice crawlers in 1914, bringing the total insect orders to 30, and the first to note them as far south as namaqualand here in Sunny SA…my inspiration to mouth off big words hehehe
enjoy