The worker termites are the main caste of the termite colony. When a new reproductive pair of alates has settled down and the queen has started laying eggs, worker termites are always the first brood to emerge from the eggs. In some species there are 2 (sometimes even 3) size versions; a major variant (which is larger and often darker), and a minor variant (which is smaller). This trait is called polymorphism, and it also occurs in many species of ants.
Worker termites perform all the important tasks of gathering food, circulating and maintaining the colony’s pheromones and food among each other via trophallaxis, tending to the eggs and nymphs, taking care of the queen and king, and constructing or repairing the nest, tunnels, galleries, feeding tunnels, and in certain species, fungi gardens. Also, the worker termites are able to perform some supplementary defensive duties when the nest is under attack, as their jaws, so adept at chewing plant matter, are also capable of self defense functions.
In species with dimorphism, the large workers mainly do the heavy tasks, like construction and foraging for food, while the small workers perform the more delicate tasks like feeding and caring for the brood.
Workers are born blind, and in many subterranean wood eating species, typically pale or white in color, hence the general concept of termites being “white ants.” In all families with the exception of the Termitidae (one of the biggest families), the worker termites have specialized bacteria in their gullet, which assists the termites in digesting the cellulose found in wood. This bacterium is probably the main reason why a proportion of termites are destructive pests while another proportion of termites are not.
Worker termites can comprise as much as 80% of a colony and they are found in large numbers in feeding locations. The sole worker termite is pretty helpless and fragile, but collectively, they are able to build elaborate structures, working like a singular brain. How they are able to coordinate all this is still a mystery – and remember, termites are blind, unlike the majority of ants.