What is one of the main duties of subterranean termite workers?

One of the main duties of subterranean termite workers is to build tunnels and shelter tubes. These structures are essential for the survival and efficiency of the colony, as they create a protective and moisture-rich environment that allows termites to travel safely to their food sources, which are typically wood and other cellulose materials. By constructing these tunnels, worker termites facilitate the movement of the colony, enabling them to forage for food while minimizing exposure to the open air, which could lead to desiccation and predation.

In contrast, the other roles mentioned in the choices are performed by different castes within the termite colony. For instance, reproduction of new members is a responsibility assigned to the queen and king termites, while laying eggs is also primarily the role of the queen. Scouting for predators, although important, is not a primary duty of worker termites. Instead, worker termites focus on nest maintenance, foraging, and caring for the colony, which highlights the importance of their role in building and maintaining tunnels and shelter tubes.