The most damaging species among termites. They must, however, be in regular contact with water. Hence, they nest underground sometimes attacking timber foundations. Subterranean termites differ from the dry-wood and damp-wood termites in that colonies usually need to maintain contact with the soil in order to acquire enough water to survive. In some cases, where structural timbers are sufficiently moist, colonies are able to survive without ground contact. The underground colony lives in a series of chambers and galleries from which they construct mud tubes to the wood which they use as food. They can also nest above the ground if there is a constant source of water such as from a leaking pipe or air-conditioner.