These mothers are the mothers of all mothers, so to speak. Hence, they are called queens. The soil-tunnelling termites have a more advanced caste system with true workers. True workers are never able to become alates although they can become soldiers and sometimes they even transform into special reproductives called ergatoids. Soldiers of subterranean termites have a gland on the head that secretes defensive chemicals.
Some soldiers have extraordinary snapping mandibles.
Many subterranean termites have specialized diets and may eat plant litter, grass, dung or humus, instead of wood. In tropical areas many subterranean termites build nests or mounds which are among the most impressive examples of animal architecture. Subterranean termites can be very serious structural pests of houses. They do not produce fecal pellets like the drywood termites. Instead, the entry of subterranean termites into a house is usually revealed by the presence of mud shelter tubes on walls.