Final answer:
Termites digest wood through a mutualistic relationship with protozoa and bacteria in their guts, which produce enzymes that break down cellulose and lignin. Subterranean termites use wood particles and fecal material to construct their tunnels, differing from other wood-boring insects.
Step-by-step explanation:
Termites are capable of digesting wood because of a mutualistic relationship with microorganisms, including protists and bacteria, that live in their guts. These microorganisms produce enzymes that break down cellulose and lignin, which are the main components of wood. Specifically, certain anaerobic protists host bacteria that produce the actual enzymes needed to digest cellulose. Through this process, termites gain the nutrients they need to survive from an otherwise indigestible source.
Furthermore, subterranean termites do not expel wood particles or fecal material outside of their galleries; they incorporate them into tunnel constructions. This behavior is unlike other wood-boring insects and helps termites maintain their environment for their habitation and the colonies they live in.