1: A partial look at the termite gut ecosystem. One of the most important protists in the gut of the C. formosanus termite (left) is P. grassii (top right), and each P. grassii cell is in turn dependent on the presence of thousands of CfPt1-2 endosymbionts (bottom right) for its survival. (Photo courtesy of Rikenreasearch.riken.jp)
Termites may eat wood, but what they are really after is the cellulose that the wood is made of. Cellulose is the most abundant organic compound on Earth and is the main component in the cell walls of plants. Cellulose is a very important material to humans and can be found either in its original form as building materials or in more refined forms such as paper and even in the food that we eat.
Although termites can consume almost any cellulosic material, they cannot actually receive any nutrition without the help of symbiotic microorganisms living in their digestive tract. These bacteria, fungi and protozoa break down the cellulose and release nutrients that can then be absorbed by the host termite.
In addition to wood and plant fibers, termites can chew through just about any material that is softer than their hardened mandibles. This includes drywall, foam, plastics and even lead (thin sheets).