The mounds are inclined to the north to reduce heating in the tropical noon.
The colour of the mound is dependant on the local soil.
In the rainy season the fruiting bodies of the fungus Termitomyces are produced. The termites use the fungi to pre-digest their hardwood food. See this page for lots more detail.
The mounds are often built under trees. This is again a thermal control adaptation. They do not seem to attack the trees which shade them.
