Sometimes, their shed wings are the only evidence that termites are present. Although the reproductives don't cause damage, swarming termites or their wings alone are sure signs that termites are working in a building. Because winged termites often are confused with winged ants, it's important to know how to tell the difference. Ants have narrow, wasp-like waists, while termites have broad waists. Also, the wings of an ant are about the same length as its body, but a termite's wings are about twice the length of its body.
Termite tubes are another danger signal to watch for.
Because they prefer dark, moist conditions, termites make these earth-colored tubes primarily as protected runways from the earth to the wood they feed on. They also may serve as swarming exits for winged termites. Look for these tubes on cellar walls, wooden posts, exterior masonry and trim around doors and windows. Wood attacked by termites has channels or passages coated with an earth-like material. Where the wood has been infested for some time, it may be largely hollowed out with passages and may look rotten.