What sign is most indicative of a subterranean termite infestation?

Mud tubes on the foundation are a clear and important sign of a subterranean termite infestation. These tubes are typically made of soil, feces, and wood particles, and they serve as protective pathways for termites as they travel between their nests in the ground and above-ground wood sources. The presence of these tubes indicates that termites are actively foraging for food and are establishing a route to their food source, which can include foundations, wooden structures, and any other cellulose-containing material in your home.

While blackened wood and rotting floorboards can indicate damage caused by pests or moisture problems, they are not exclusively linked to subterranean termites. Swarming insects indoors may indicate a termite presence, but it could also be indicative of other types of insects. Mud tubes are thus the most specific and reliable evidence of subterranean termite activities, making them the key identification marker for this type of infestation.