Why can't soldier termites feed themselves?

Soldier termites cannot feed themselves because they have evolved to specialize in defense rather than foraging or feeding. This specialization results in a significant morphological change; soldiers possess heavily fortified bodies and strong jaws, which are specifically adapted for protecting the colony from predators. Their mandibles are indeed well-developed, but their mouthparts are not suited for the typical feeding function seen in worker termites. Consequently, soldier termites rely on the worker termites for feeding, as the latter are responsible for gathering food and caring for the colony's needs. Therefore, the specialization of soldier termites for defense is the primary reason they cannot feed independently.