Soldier termites are responsible for the protection of the colony. These insects are built to defend against any predators or invaders, and keep the colony productive and strong.
Soldier termites are equipped with large, solid heads that are very hard. They also have strong mandibles, which are much stronger and larger than other termite's mandibles in the colony. The soldiers position themselves at the opening of the termite nest and stand guard.
Soldiers are critical members of the termite colony. They are fed by the workers and are eyeless, like the reproductive colony members. Soldiers will seek enemies by scent. Each termite colony produces its own scent, so if a soldier smells an unfamiliar scent, it will attack.
With all colony living insects, such as bees or ants, communication is a critical factor to the success of that colony. Termite soldiers communicate danger not only by scents, but also by sound. When a threat is perceived, the soldier termite will bang its large, solid head against the walls of the mud tunnels or living areas. This serves to warn the other termites of danger.
Termites also communicate through trophallaxis. This is the exchange of food and nutrients between colony members. Soldier termites will be fed the food they need by workers, as well as digestive nutrients to help them process that food.
Termites also exchange chemicals to help them identify each other. This also serves to limit certain populations of castes so they don't grow too large. For example, if too many soldiers are found to be in the colony, as identified by these chemicals, the chemicals will limit the number of soldiers produced in the immediate future. The chemicals will also trigger soldiers to be killed by other termites to maintain the level of the population.