Termites play an important role in the natural ecological cycle. They feed on cellulose, the principal ingredient of wood, and help to break down dead trees in forests and other wooded areas, thus enriching the soil. Termites began attacking houses when the wooded areas were cleared for building construction and there was no other available source of food near their nest. Subterranean termites are found in every state except Alaska. Their overall distribution within the continental United States is shown in FIG. 8-1. As their name implies, subterranean termites live in a colony (nest) that is usually located in the ground below the frost line. Even when a house is infested with termites, they usually do not have a nest in the house. They are there only to gather food. The only condition under which a nest might exist in a house (a rare occurrence) is a constant source of moisture such as a leaky waterpipe or drainpipe that wets the surrounding area.
Termites are social insects. Within each colony, there is a rigid caste system consisting of a queen and king, workers, soldiers, and reproductives. Each member of the colony instinctively performs its special task. The function of the queen and king is to propagate the colony. The fertilized queen lays the eggs and might live for as long as twenty-five years. The workers care for the eggs, feed the young and the queen, and generally maintain the colony. They also forage from the nest to the wood supply and return with food. The soldiers defend the colony against attack by other insects, mostly ants. The average worker and soldier live only two or three years. The function of the reproductives is to replace the queen and king in the event of their injury or death. They also lay eggs that rapidly increase the termite population.
When a colony matures, reproductives leave the nest (swarm) to set up a new colony. Although thousands of reproductives leave the nest, only a handful survive to establish a new colony. The remainder die because of adverse conditions in the soil or attacks by other insects. Reproductive termites sprout wings for the swarm. With their wings, they are only about 1⁄2 inch long. They are considered poor fliers and generally flutter around before falling to the ground. Some, however, might be picked up in the wind and carried great distances. Once the reproductives land, they shed their wings, pair off in couples, and return to the soil in search of a suitable place to build a nest.
In most parts of the country, swarming generally occurs in the spring, sometimes in the fall. However, swarming termites have been found in January in some heated houses. In the warm, humid parts of the country, swarming can occur at any time. Even if there are no other outward signs of termite activity, termite swarming in a house is an indication that there is a healthy established colony nearby from which worker termites are coming in their search for food.
Swarming termites do not attack wood. Their only function is to start a new colony. Even if a swarm is in your house, you might not see it. A swarm might last from fifteen minutes to one hour, and if you are not in the right place at the right time, it can be over by the time you enter the room. However, if there was a swarm, you can tell by the discarded wings. They are often found on windowsills and light fixtures, and beneath doors. Do not confuse swarming termites with swarming ants. To the untrained eye, they appear similar, but there are distinctive differences. (See FIG. 8-2.) The most obvious difference is that termites have a thick waist and ants have a pinched (hourglass) waist.