They have large mandibles and heavily armored heads. The workers are the most populous caste, and they are responsible for building the nest and galleries, cleaning and maintaining the nest, collecting food and feeding the members of the soldier and reproductive castes. Ants are the primary animal predators of termites. Termites are an important source of food for many animals, including humans. By tunneling through wood termites create entryways for moisture and decay fungi to speed the decomposition of wood into humus.
Termites derive their nutrition from the cellulose that is contained in the wood.
The digestion of the wood is accomplished by microbial bacteria and protozoans that reside in the intestinal tract of the termites. In fact, it has been shown that if these micro-organisms are artificially removed from the termite gut, the termite will starve to death even though it continues to feed on wood.