This Cubitermes nest (probably a Cubitermes fungifaber) presents externally the « mushroom shaped » appearance typical of Cubitermes nests. It is thought (Guy Josens, personal communication) that the external shape of the nest represents an adaptation to confer protection against heavy rain: the top “hat” would act as a sort of umbrella that protects the nest walls from rain (possibly to favour gas exchange: the permeability to gas is reduced when clay is wet).
Inside, the nest is fully packed with oval chambers, all similar in size, interconnected by very short and narrow corridors. These narrow corridors might serve a defence purpose. In fact, some specialised termites in the colony -the soldiers- defend the colony from predators such as ants by blocking completely these corridors with their large and strong head.
If the arrangement of chambers and corridors is apparently chaotic, mapping the whole network of interconnections reveals some organisation, with a few vertical “highways” near the centre of the nest and sparsely connected peripheral chambers.