Subterranean termites are social insects that live in colonies containing caste systems. Typical colonies have three distinct castes: reproductives, workers and soldiers. The reproductives, including the queen and king, are responsible for mating and populating the colony. A queen is the largest and most important termite found in the colony, producing up to 1,000 eggs per day. The workers are the largest group in most termite colonies, repairing the nest, grooming and caring for nest mates, and foraging for food. Soldiers, equipped with huge armored heads and sharp, enlarged mandibles, defend the colony from attack. The queen may live for many years, and individual soldiers and workers may live one to two years. During certain times of the year, “swarmers” will emerge from colonies. These winged adult reproductives leave the current colony to form their own. They typically only produce a few eggs in the first year, but once the colony’s queen matures she will produce about 5,000-10,000 eggs a year. It typically takes several years, often between five and 10, before a colony reaches a mature size of at least 60,000 termites.
A typical, mature subterranean termite colony can consist of anywhere between 60,000 and two million workers. Subterranean termites use their scissor-like jaws to eat wood 24 hours a day, seven days a week. Like other termite species, subterranean termites also feed on products containing cellulose.
Subterranean termites typically swarm in the spring across the U.S., and in late winter in Florida, when groups of reproductive termites go off to start new colonies. However, it’s possible for one or more smaller swarms to occur during the winter if inside heated structures. Characteristically, termite swarming happens during the daytime, especially during the morning of a day following warm, rainy weather.
Traveling through their distinctive mud tubes, subterranean termites can enter structures through cracks less than 1/16" (1-2 mm) wide. However, if a constant source of moisture is available, such as leaky pipes, colonies can also exist above the ground. “True aerial” colonies, which have no contact with the ground, are also known to exist. In any given building with a subterranean termite infestation, there may be several colonies co-existing at once.
Subterranean termites have been found in nearly every state in the U.S. In some southern areas, the moist and warm climate provides the ideal conditions for these silent destroyers to wreak havoc on homes and other structures. In the extreme northern states and Canada, it’s less common to see swarmers. There, the colonies’ distributions are patchy because the termites are usually spread in infested wood and wood products, such as lumber and firewood. Colony sizes are much larger. In fact, it’s not uncommon for these colonies to have 2-3 million foragers. These large colonies forage over bigger areas and actively feed in living trees and free-standing poles, in addition to structures.