What type of tubes do subterranean termites construct?

Subterranean termites construct mud-covered tubes as a protective measure for their colonies. These tubes are built from soil, wood particles, and saliva, which help to shield them from predators and maintain the moisture levels necessary for their survival. The mud tubes serve as highways for termites, allowing them to travel between their underground nests and above-ground food sources while avoiding exposure to the open air, which can be detrimental to their delicate bodies.

The correct choice highlights the specific construction materials and characteristics of the tunnels that subterranean termites create, emphasizing their adaptation to their environment and their need for moisture and protection. This behavior is crucial for the survival and efficiency of their colony. In contrast, the other options do not accurately describe the nature of the structures built by subterranean termites.