Habits of Termites
Although woody plants and wood products are eaten by most termites, some eat grass, leaf mold, manure, algae, and soil. Some termites cultivate fungi as food for the colony. Wood-eating termites have protozoans (one-celled organisms) in their digestive tracts. The protozoans digest cellulose, a fibrous substance in the wood, breaking it down into substances that are easily absorbed by the termites' digestive system.
Termite nests (termitaria)vary greatly from one species of termites to another. Subterranean termites burrow long tunnels in the earth in which they live and from which they invade plants and wooden structures that are in contact with the ground. If they do not have direct access, they build shelter tubes, tubes of mud and body excretions that serve as passageways from their nests to food sources. Shelter tubes prevent outside air from entering the colony, thus keeping it humid and damp; if the colony becomes too dry, the termites die.
Damp-wood termites inhabit chambers in damp, rotting wood or in living woody plants. Dry-wood termites inhabit dry, dead wood, including that used in manmade structures, such as houses and furniture. Both types of wood termites build shelter tubes, using digested wood.
Some tropical termites build nests in trees or on top of the ground. These nests may be of chewed wood, wood debris, or earth. Nests on the ground may be conical, mushroom-shaped, or made up of one or more vertical cylinders. They range in height from 1 to 30 feet (60 cm to 9 m), and the more elaborate ones may be 15 feet (4.5 m) in diameter.
Most species of termites tunnel down, building nests underground or in trees or wood buildings. But some species build up! These master builders live in Africa, Australia, Asia, and South America. Some build towers up to 30 feet (over 9 meters) high.
How do termites build towers? When termites dig, they bring the soil to the surface. They mix their saliva with the soil so that it hardens. The more soil the termites dig, the higher the tower grows.
Termite towers have a special purpose: to warm and cool the nest. Australian compass termites build towers with flat sides that face north and south. The flat sides catch the sun’s rays in the morning and evening to warm the nest. The pointed top deflects the hot noonday sun.
The fungus-growing termites of Africa have towers that are mostly hollow. Hollow towers act like chimneys, letting the hot air rise. Small tunnels down the sides let fresh air in, keeping the queen cool.
Once or twice a year, well-established colonies produce swarms of winged reproductives which may number in the millions. Many are caught on the wing by birds and bats. The survivors drop to the ground and break off their wings. Males and females, often from different colonies, pair off and start building a nest. Later, they mate and together tend the first small broods of eggs and nymphs.
For several years the colony produces only workers and soldiers. After three or four years, reproductives are produced. The workers tend the reproductives, young, and eggs. They also forage and enlarge the nest. The soldiers guard the nest from small enemies, such as insects, but they are helpless against such large predators as anteaters and chimpanzees. The number of eggs laid by the queen increases through the years until she is producing about 10,000 a day during most of her life. A queen may live for 50 years. Secondary and tertiary reproductives develop from nymphs, usually after the death of one or both of the primary reproductives. In certain species, some soldiers lay eggs.
