Subterranean termites can cause the most damage of any termite species. These termites build distinctive tunnels, often referred to as “mud tubes,” to reach food sources and protect themselves from open air. They eat wood 24 hours a day, seven days a week, using their saw-toothed jaws to bite off small fragments of wood one piece at a time. Over time, subterranean termites can critically damage a building structure, sometimes causing a total collapse.