Termites live in every U.S. state except Alaska. They’re most concentrated in the warm, humid Southeast and along the Gulf Coast, but different species have adapted to climates ranging from the dry Southwest to the Pacific Northwest. Where you live determines which type of termite you’re most likely to encounter, and each type nests in different places around (and inside) a home.
Subterranean Termites: Nearly Nationwide
Subterranean termites are the most widespread group in the country and the most economically destructive. The eastern subterranean termite is the single most common species, found throughout the eastern United States from Maine to Florida and as far west as Texas. Related species fill in the Southeast, though they cause less structural damage because their colonies tend to be smaller.
In the western half of the country, the western subterranean termite takes over, causing damage to structures across the Pacific Northwest and into California. Desert subterranean termites are active in Arizona, New Mexico, and parts of West Texas. As a rule, subterranean termites are most abundant and most aggressive in warmer climates, where colonies can grow year-round. In northern states they still exist, but the colder winters slow colony growth and reduce the likelihood of serious structural damage.
These termites nest underground in the soil, often several feet below the surface. They reach wood by building mud shelter tubes, pencil-width tunnels made of soil and saliva, up foundation walls, support piers, plumbing pipes, or any other surface that bridges the gap between ground and wood. You’ll most commonly spot these tubes on exterior foundation walls, inside crawl spaces, or running up support posts under a house. Subterranean termites can also tunnel through foam insulation to reach wood framing hidden behind it.
Formosan Termites: The Gulf Coast and Beyond
Formosan subterranean termites are an invasive species that arrived in the U.S. on military cargo ships after World War II, landing first in port cities like Galveston, Houston, New Orleans, Lake Charles, and Charleston. They’ve since spread across much of the southern tier of the country. Established populations now exist in Alabama, Arizona, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, South Carolina, Texas, and Virginia. Hawaii has dealt with Formosan termites even longer, with infestations predating the mainland arrivals.
What makes Formosan termites especially destructive is their colony size. A single colony can contain millions of workers, compared to hundreds of thousands for native subterranean species. They also nest differently. While they live underground like other subterranean termites, Formosan colonies can build secondary nests called cartons inside walls, attics, and other above-ground spaces if enough moisture is available. These cartons are dense masses of chewed wood, soil, and saliva that let the colony survive without a direct connection to the ground.
Signs of Formosan activity look different from typical subterranean termites. They build horizontal streaks of dried mud along eaves and soffits, and in late spring they construct odd mushroom-shaped mud formations on walls and ceilings called “swarm castles,” which serve as launching points for their mating flights. New Orleans has been hit particularly hard, with infestations documented across residential neighborhoods, schools, and historic buildings in Orleans, Jefferson, and St. Bernard Parishes.
Drywood Termites: Southern and Coastal Areas
Drywood termites have a much narrower range than subterranean species. They need warm temperatures and are limited to a band across the southern United States. The dark southern drywood termite lives from central Florida up through the Carolinas. The western drywood termite is a major pest in Southern California, Arizona, and other parts of the arid Southwest.
Unlike subterranean termites, drywood termites don’t live in the soil at all. They nest entirely inside the wood they eat, whether that’s a structural beam, a piece of furniture, or a door frame. A colony establishes when a mating pair lands on exposed wood, bores in, and seals the entrance behind them. The entire colony, sometimes just a few thousand individuals, lives within that single piece of wood for years.
Because they leave no mud tubes and don’t need ground contact, drywood termites are harder to detect. The most reliable sign is finding small, six-sided fecal pellets, about the size of a BB, accumulating on floors, windowsills, or countertops below infested wood. The termites push these dry pellets out through tiny “kick-out holes” in the wood’s surface. You might also notice blistering or peeling paint on walls where the colony has hollowed out the wood underneath.
Dampwood Termites: The Pacific Northwest
Dampwood termites are the least likely to damage a well-maintained home, but they’re common in the Pacific Northwest. The Pacific dampwood termite is found throughout Oregon, Washington, and into Northern California. As the name suggests, these termites need wood with high moisture content. They nest inside and consume damp, water-damaged, or decaying wood rather than building colonies in the soil.
In nature, dampwood termites play an important role breaking down fallen logs and stumps. They become a structural problem only when a building has a persistent moisture issue: a leaky roof, poor drainage, wood-to-soil contact, or plumbing that’s been dripping into framing for months. Fixing the moisture source is usually enough to make conditions inhospitable for them. A smaller species of dampwood termite also exists in parts of Florida, but it rarely causes significant structural damage.
The Highest-Risk Regions
Termite pressure varies enormously across the country. The U.S. Department of Agriculture divides the continental states into termite infestation probability zones, and the pattern follows temperature and humidity closely. The zone of heaviest termite activity stretches from the Carolinas through Georgia, Alabama, Mississippi, Louisiana, and into East Texas. Florida is especially hard-hit because it has both subterranean and drywood species active year-round, along with Formosan colonies in urban areas. Southern California faces a different combination: western subterranean termites in the soil and western drywood termites in the wood above.
Moderate termite risk extends through the Mid-Atlantic, Midwest, and into the mountain states. Termites are present, but shorter warm seasons and drier conditions keep colony sizes smaller and infestations less frequent. The northern tier of states, from the Dakotas through Minnesota, Wisconsin, and into New England, has the lowest risk. Termites exist there, but damage is uncommon enough that many homeowners never encounter them.
Where Termites Nest on a Property
Regardless of species, termites on a residential property tend to concentrate in predictable spots. Subterranean colonies in the yard often center around stumps, buried roots, woodpiles, railroad ties, or landscape timbers. Finding active termites in a stump or log 25 feet or more from your foundation doesn’t necessarily mean your house is infested, but it confirms colonies are nearby.
On the structure itself, subterranean termites enter where wood is closest to soil. Mud tubes running up the foundation are the classic sign, but they also exploit gaps where siding meets the slab, cracks in concrete, expansion joints, and the space around plumbing or electrical conduits that penetrate the foundation. Once inside, they feed on framing, subfloor, sheetrock paper, and wood paneling. You might notice sunken trails under the paint on drywall, small dots of dried mud on interior walls, or soft spots in flooring.
Drywood termites enter higher up. They infest attic framing, window frames, eaves, fascia boards, and even furniture. Because they fly directly to exposed wood during mating flights, any unprotected wood surface on the exterior of a home is a potential entry point. Their colonies are small and localized, so it’s possible to have an infestation in one rafter that hasn’t spread to adjacent wood.