There are over 2,700 known species of termites throughout the world. In the U.S., subterranean termites, including Eastern, Western, desert and Formosans, are a concern in every state except Alaska. Subterranean termites, which build underground nests, can be extremely destructive. They can tunnel to wooden structures (like your home), which damage by using it as a food source. Termites all share a virtually insatiable appetite for wood and other cellulose-containing materials. Given enough time, they can cause extensive damage and will feed on the wood until nothing is left but a shell.