Texas is home to several termite species, but two groups cause the vast majority of structural damage: subterranean termites (both native and Formosan) and drywood termites. Where you live in the state, what time of year you spot swarmers, and what kind of evidence you find all point to which type you’re dealing with, and that matters because each requires a different approach to control.
Native Subterranean Termites
Native subterranean termites in the genus Reticulitermes are found throughout Texas and across the entire United States. They’re considered the most economically important termite group in the country simply because of how widely distributed they are. These termites live in underground colonies and travel through soil to reach wood, building pencil-width mud tubes up foundation walls, support piers, and plumbing lines to stay protected from open air as they move between their colony and your home.
A mature native subterranean colony contains tens of thousands of workers, and they feed on any wood that contacts or sits near the soil. Damage from these termites shows up as hollowed-out galleries inside structural timbers, and those galleries will contain dried dirt. You might also notice sunken, winding lines under paint or wallpaper where workers have been feeding on the paper backing of drywall just beneath the surface. Small, BB-sized spots of dried mud on interior walls or ceilings are another telltale sign. These “pinholes” appear when workers accidentally break through to the outside and quickly patch the opening with mud.
Formosan Subterranean Termites
The Formosan subterranean termite is an invasive species originally from East Asia that has become an increasingly serious problem in Texas, particularly in the eastern half of the state and along the Gulf Coast. Formosan colonies are dramatically larger than native subterranean colonies, sometimes containing several million individuals. That size difference translates directly into speed of damage: a Formosan colony can cause noticeable structural harm in months rather than years.
Formosan termites behave differently in ways you can spot. Their mud tubes tend to appear higher on a building, running up interior walls, ceilings, exterior soffits, and fascia boards, rather than just along the foundation. They also build distinctive “swarm castles,” odd-shaped formations of dried mud that sprout from walls or ceilings in late spring as the colony prepares to release winged swarmers. Formosan termites are also more aggressive about traveling through foam insulation board, building extensive tunnel networks through it to access wood above.
One key behavioral difference: Formosan termites can establish secondary nests called carton nests above ground, inside walls or other enclosed spaces, using a mixture of chewed wood, soil, and saliva. This means they don’t always need to return to the ground, making them harder to control with soil-based treatments alone.
Drywood Termites
Drywood termites are more common in coastal areas of Texas, particularly around Houston, Corpus Christi, and other Gulf-adjacent cities. Unlike subterranean species, drywood termites don’t need soil contact at all. They live entirely inside the wood they’re eating, whether that’s a wall stud, a piece of furniture, or a fascia board. Small colonies can survive for years inside a single piece of lumber.
The clearest sign of drywood termites is their frass: tiny, uniform, six-sided pellets that look like coarse sand or pepper. Drywood termites push these dry fecal pellets out of small “kick-out holes” in the wood, and you’ll typically find neat little piles on a floor, windowsill, or countertop below the infested area. There are no mud tubes, no soil connections, and no mud-filled galleries. If you see small piles of granular pellets appearing repeatedly in the same spot, that’s almost certainly a drywood infestation.
Swarming Season Across Texas
Swarming is how termite colonies reproduce. Winged termites (called alates or swarmers) leave the colony, pair off, and attempt to start new colonies. The timing varies significantly depending on where you are in Texas. In South Texas, swarming can begin as early as January or February. In central Texas, it typically starts in late March or early April. Up in the Panhandle, swarms may not appear until April or May.
The process usually begins with the construction of a swarm tube, a small mud structure near the soil surface or on a wall. Within a week or two, when temperature and humidity conditions are right (often after a warm rain), that small opening becomes a doorway for dozens to thousands of winged termites. Native subterranean termites generally swarm during the day in spring, while Formosan termites swarm at night, usually in late spring or early summer, and are strongly attracted to lights. Drywood termite swarmers tend to appear in late summer or early fall.
Finding swarmers inside your home is a strong indicator that a colony is already established nearby. Finding them outside, especially near exterior lights, doesn’t necessarily mean your structure is infested, but it does mean colonies are active in the area.
How to Tell Which Type You Have
The evidence each species leaves behind is distinct enough that you can usually narrow it down before a professional arrives:
- Mud tubes on foundation walls or piers: Native subterranean termites. The tubes run from the soil upward along concrete, brick, or plumbing.
- Mud tubes high on walls, ceilings, or soffits: Likely Formosan subterranean termites, which build more extensive above-ground networks.
- Small piles of six-sided pellets: Drywood termites. No mud, no soil connection.
- Damaged wood with dirt-filled galleries: Subterranean termites (either native or Formosan).
- Dried mud formations on walls or ceilings in spring: Formosan swarm castles.
Treatment Depends on the Species
Subterranean termites are treated primarily through the soil, since that’s where their colony lives. For new construction, soil is treated with termiticide before the slab or foundation is poured. For existing homes, a post-construction soil treatment involves trenching around the foundation and applying termiticide to create a chemical barrier between the colony and the structure. Bait systems are another option: plastic stations are installed in the ground around the home, each containing wood or cellulose slats. Pest control companies monitor these stations regularly, and once termites are found feeding in them, the wood is replaced with bait treated with a slow-acting termiticide. Workers carry the bait back to the colony, where it spreads and gradually kills other members.
Drywood termites require a completely different approach because they have no soil connection to target. Your options are spot treatment (injecting termiticide directly into infested wood), physical removal of the infested lumber, or whole-structure fumigation. The Texas Department of Agriculture notes that fumigation with a wood-penetrating gas is the only method that reliably eliminates every drywood termite in a structure, since colonies can be hidden deep inside walls where spot treatments can’t reach. Fumigation requires you to leave your home for several days while the building is tented and treated.
Because Formosan termites can nest above ground inside carton nests, soil treatments alone sometimes aren’t enough. A combination of soil barriers, bait systems, and direct treatment of any above-ground nests is typically needed for Formosan infestations.
Regional Risk Across the State
Every part of Texas has termite pressure, but the type and intensity vary by region. The Gulf Coast and East Texas see the highest risk overall, with all three types (native subterranean, Formosan, and drywood) present. Formosan populations are concentrated in urban areas near the coast, particularly Houston, Beaumont, and Galveston. Drywood termites are most common in coastal cities like Houston and Corpus Christi, though they can appear anywhere wood is transported.
Central Texas, including the Austin and San Antonio corridors, deals primarily with native subterranean termites. West Texas and the Panhandle have lower overall termite pressure due to drier conditions, but native subterranean species are still active, particularly in irrigated landscapes and areas where soil moisture accumulates near foundations. Even in arid parts of the state, homes with poor drainage or heavy landscaping near the foundation can create conditions that support subterranean colonies.