Although termites feed on wood, many, if not all, species cannot digest it on their own, so they have protozoa in their digestive tract that break down cellulose in their place. Without them, termites would die. They are not born with them and young people acquire them in the pre-digested food provided to them by other members of society. Every time the termite molts, it loses its protozoa, but as it shares its food with its congeners, it is infested again.
Despite the propensity of some species to devour wood, not all termites are undesirable. In nature, they recycle wood into compounds useful to other living beings. In the tropics, they play the same role as earthworms in temperate regions; stirring the organic matter of the soil, they aerate it and dig galleries where water loaded with minerals can circulate.
What Are The Termites That Do Not Live In The Wood?
Termites that eat wood do not necessarily live in it. Dry wood species, which form small colonies (a few hundred individuals), can actually nest there, but the harmful species of temperate climates live mainly in the ground, and their workers circulate in tunnels from the earth to food sources.
Dry savannah termites build impressive dome-shaped termite mounds, or pyramidals, sometimes lined with needles or chimneys up to 9 m high. Most of these dwellings have a double wall. The outer wall, hard as concrete, is made of cemented grains of sand. The internal partition and galleries are lined with a kind of cardboard.
In humid tropical regions, termites build their nests in trees. These nests, made of cardboard, may have a kind of roof on which rain flows, but covered galleries connect them to the ground.
Compass termites in northern Australia build termite mounds in the shape of a flattened wedge. The wide, flat sides are always directed to the east and west, while the thinnest ends are to the north and south, an orientation that is believed to facilitate temperature control inside the nest.