Termites are sometimes referred to as ‘white ants’, but they are not ants and are not related to them. They are most abundant in tropical and sub-tropical countries where, in some cases, their ‘nests give rise to large, prominent mounds. All termites form extensive colonies with one egg-laying queen and hundreds or thousands of workers. The workers are nymphs whose development to reproductive adults is suppressed. Most of them carry out duties in the nest, feeding the queen and the young, nest building and collecting food but some workers develop into ‘soldiers’ with large heads and long jaws. Their job is to defend the nest from intruders.
At certain times of the year, some of the workers complete their development and become winged adults, both male and female. These leave the nest in dense swarms and eventually land on the ground, shed their wings and mate. The female then lays eggs in the soil and so starts a new colony. Macrotermes bellicosus is an African termite which can build spectacular mounds. The workers build the mounds by combining sand and clay with their saliva. Just above ground there is a central ‘nest’ with a network of tunnels many of which connect with underground passages leading to a good source of food. In the nest, the queen does nothing but produce eggs. Her abdomen swells so much that she cannot move and the workers feed her and carry away the eggs as fast as she can lay them.
Termites feed exclusively on plant material, mainly the cellulose in woody tissues. Some termites can digest the cellulose, sometimes with the aid of a population of single-celled organisms in their gut, but Macrotermes brings the plant material back to the nest and chews it to a pulp. On beds of this chewed pulp and termite faeces, fungi grow. Macrotermes feeds on the fungi or on the wood pulp which has been partially digested by the fungus.
If termites burrow into wooden structures to obtain their cellulose, they cause damage.