What distinguishes drywood termite soldiers from other castes?

Drywood termite soldiers are characterized by their distinctive mandibles, which feature ridges. This feature distinguishes them from other castes within the colony, particularly the workers and the reproductives. The soldiers have a physically robust form adapted for defending the colony against predators, and their mandibles are an essential tool for this purpose. The ridges on their mandibles enhance their ability to grasp and fend off threats, showcasing their role as protectors within the colony structure.

In contrast, other castes, such as the workers, have mandibles that are structured for different functions, such as foraging and tunneling. The reproductives, which include the king and queen, do not have pronounced mandibles like the soldiers do, as their role is primarily focused on reproduction rather than defense. Thus, the notable feature of ridged mandibles in soldiers clearly sets them apart within the caste system of drywood termites.