They search outside their nest for wood to feed on and construct earthen tubes from the nest to the food source. Nests appear to be designed to maintain high humidity. Termites very quickly die from loss of body fluids if exposed to outside conditions for very long. A break in the nest structure will quickly be detected and repaired by workers. The most common way to detect termites is spotting the winged adults emerging from inside a building, generally in the spring or fall.
Termites often fly to windows or other light sources.