What distinctive features do soldier termites possess?

Soldier termites are characterized by their greatly enlarged reddish-brown heads and prominent mandibles, which are often sword-like in appearance. These adaptations serve critical functions in the colony's defense. The soldier's large head and strong mandibles enable them to effectively protect the colony from predators, such as ants and other threats. Their physical traits are specifically evolved for combat and defense, making them a crucial component of the termite colony's social structure.

The other options describe characteristics that do not fit soldier termites. For example, long antennae and small eyes are more typical of other castes within the termite colony, like workers or reproductive termites, which rely on different sensory and functional adaptations. Similarly, the soft bodies and lack of mouthparts are typical of termite nymphs, not soldiers. Lastly, bright coloration and large wings describe the reproductive caste, which is different from the soldier caste focused solely on protection and does not possess wings.