Termite advice online often treats drywood and subterranean termites as equal threats everywhere in the South. In the Carolinas and Virginia they aren't. Subterranean termites, including the aggressive Formosan termite in parts of both Carolinas, cause nearly all the damage. Drywood termites are mostly a coastal South Carolina issue. Here's how to tell them apart, where each actually lives in our three states, and why the difference decides the treatment.
Subterranean termites live in the soil and build pencil-width mud tubes up foundations. They're the main termite problem across SC, NC and VA. Drywood termites live entirely inside dry wood, make no mud tubes, and push out piles of tiny, hard pellets.
Where: Clemson says drywood termites are most common along South Carolina's humid coast. NC State calls them "relatively uncommon in North Carolina," and Virginia Tech says they're "very uncommon in Virginia." The two need completely different treatments: soil treatment or baits for subterraneans, and fumigation or targeted wood treatment for drywoods.
Drywood vs. Subterranean: Side by Side
| Subterranean (incl. Formosan) | Drywood | |
|---|---|---|
| Lives | Colony in the soil. Travels into the house through mud tubes | Entirely inside the wood it eats. No soil contact |
| Key sign | Mud tubes on foundations, piers and crawl space walls | Piles of tiny hard pellets below infested wood |
| Damaged wood | Galleries lined with soil. NC State notes a "thin gritty gray-brown film" on damaged surfaces | Clean, smooth galleries cut across and with the grain (Clemson) |
| Colony size | Native: 200,000 to 2 million workers in a mature colony, though many have as few as 50,000 to 60,000 (NC State). Formosan: millions | Small and slow. Clemson: under 50 workers after two years |
| Swarming | Native: daytime, late winter into fall, often warm days after rain. Formosan: evenings, mid-May to July, drawn to lights | Colonies take 4+ years to produce swarmers |
| Where in our area | Statewide in all three states | Mainly coastal SC. Uncommon in NC, very uncommon in VA |
| Treatment | Liquid soil treatment or bait systems | Fumigation, or localized treatment of infested wood |
Subterranean Termites: The Termite You're Most Likely to Have
NC State Extension is direct: "In North Carolina, our main problem is with subterranean termites." Virginia Tech says the same of Virginia, where the eastern subterranean termite is the most common species. These termites nest in soil, need its moisture, and reach the wood in your house through mud tubes they build up foundation walls, piers and plumbing. They eat from the ground up: sill plates, floor joists, subfloors, and framing near the foundation.
Signs to look for
- Mud tubes about the width of a pencil on the foundation, piers or crawl space walls. Break a section open. Live pale workers inside means an active colony.
- Swarmers or shed wings on windowsills and near lights. NC State says native subterraneans swarm in daytime from late winter into September or October, often on warm days after rain.
- Hollow-sounding wood when tapped, and a thin gritty film on damaged surfaces (NC State).
Formosan Termites: Where They Really Are
The Formosan subterranean termite is the one to worry about, and its range is specific:
- South Carolina: introduced at Charleston in the mid-1950s and now recorded in 16 counties, according to Clemson: Aiken, Bamberg, Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, Jasper, Lexington, Orangeburg, Pickens, Richland, Sumter and York. Clemson notes the York and Pickens finds were isolated cases from infested railroad ties that were treated, with no Formosans found there since. Formosan swarms happen in the evening, mid-May to July, and swarmers are drawn to lights. On Reddit, Charleston residents describe finding swarmers in their beds and bathrooms upstairs at night.
- North Carolina: first detected in Brunswick County in 1992, in landscaping railroad ties, and established only in coastal southeastern North Carolina (NC State), not the Triangle or the Piedmont.
- Virginia: confirmed at a single Norfolk property in 2022. That's a detection, not an established population.
Formosan colonies can number in the millions. A Charleston study cited by Clemson found 94% of infested buildings were infested from colonies in the ground. That's why inspection and treatment still focus on the soil.
A 2018 demonstration in New Orleans showed what a Formosan colony can do. The National Pest Management Association built a miniature house with joists, studs, insulation, wiring and plumbing, then put more than 500,000 Formosan termites in the soil around it. In NOLA.com's YouTube report (about 491,000 views), the team says that after about two months they first saw mud tubes, then peeled back the drywall to find some joists completely gone and replaced by mud. They called the house a total loss. It was a deliberately extreme setup, but it shows why Formosan activity gets treated as urgent.
Drywood Termites: Mostly a Coastal South Carolina Issue
Drywood termites don't need soil. They live their whole lives inside the wood they eat: furniture, trim, window and door frames, attic framing. Here's what each state's extension service says:
- South Carolina: Clemson lists three drywood species and says they're "most common along humid, coastal areas of South Carolina." The southeastern drywood termite is the most common. The West Indian powderpost termite has been recorded in seven SC counties, from Charleston and Beaufort to several Upstate counties, and only inside buildings. It has never been recorded in the wild in South Carolina and moves around in infested furniture and wood.
- North Carolina: NC State calls drywood termites "relatively uncommon in North Carolina."
- Virginia: Virginia Tech says drywood termites are "very uncommon in Virginia but have been found in a few locations," usually in furniture.
The telltale sign: pellets
Drywood termites push their droppings out of tiny holes in the wood. Clemson describes the pellets as about 1/16 inch long, black, cream-colored or both, with a "salt and pepper" look, often piled "like tiny stones." Subterranean termites don't make these piles.
Before you panic over a pile of pellets, rule out rodents. On Reddit's termite forum, people in Virginia and central North Carolina regularly post "is this drywood frass?" and are told the droppings are from mice or rats. In NC and VA that's the far more likely answer. If you're unsure, Virginia Tech suggests bringing a sample to your local extension office.
Why the Type Decides the Treatment
Subterranean and Formosan termites
NC State lists two standard approaches:
- Liquid soil treatment ("trench and treat"): termiticide applied to the soil along and beneath the foundation, creating a treated zone the termites cross.
- Bait systems: stations in the ground around the house. Termites feed on the bait and share it through the colony.
Which is right depends on the house, the construction and whether termites are active now. See our termite control page for how we choose.
Drywood termites
Soil treatments and bait stations do nothing for drywood termites, because the colony never touches the ground. Clemson lists the options: remove and replace the infested wood, inject insecticide into the galleries, freeze small infested items, or fumigate the whole structure for widespread infestations. NC State notes most residential fumigations are done for drywood termites (or for wood-boring beetles in log homes), which is why fumigation is rare for subterranean termites.
What to Do If You Find Signs
- Don't disturb the evidence. Leave mud tubes intact and save a few pellets or swarmers in a zip-top bag.
- Note where you found it. Tubes at the foundation point to subterraneans. Pellets falling from furniture or trim on the coast point to drywoods.
- Rule out lookalikes: flying ants (pinched waist, bent antennae) and rodent droppings.
- Get a professional inspection to confirm the species before choosing a treatment. See the signs of termites.
In the Charleston area, where both Formosan and drywood termites occur, see our Charleston termite control page.
Key Takeaways
- Subterranean termites are the main problem across SC, NC and VA. Look for mud tubes.
- Formosan termites have been recorded in 16 SC counties and coastal southeastern NC, with a single 2022 detection in Norfolk, VA.
- Drywood termites are mainly a coastal SC issue. They're uncommon in NC and very uncommon in VA.
- Drywood sign: piles of tiny hard "salt and pepper" pellets. Rule out mouse and rat droppings first.
- Treatment differs: soil or bait for subterraneans, fumigation or wood treatment for drywoods.
Sources: P. Alder and C. Hayes, "Termites: Biology and Control", NC State Extension, updated 2026; P. A. Zungoli and E. P. Benson, "Drywood Termites", Clemson Cooperative Extension HGIC; Clemson Cooperative Extension HGIC, "Formosan Subterranean Termites", "Formosan Termites Increase Distribution in SC" (2022) and "Termites of South Carolina"; Virginia Tech Department of Entomology, Identification of Termites (archived); NC State Extension records of Formosan termites in North Carolina; Pest Management Professional, "Formosan termites expand northward into Virginia" (2022); NOLA.com, "New Orleans termites eat a tiny house from the inside out", YouTube (2018); homeowner accounts from Reddit (via Google search excerpts).
Frequently Asked Questions
Subterranean termites build pencil-width mud tubes from the soil up your foundation and leave soil-lined galleries in the wood. Drywood termites live entirely inside dry wood, make no mud tubes, and push out piles of tiny hard pellets. Clemson describes those as about 1/16 inch, with a salt-and-pepper look.
Yes, mainly along the humid coast. Clemson lists three drywood species in South Carolina, with the southeastern drywood termite the most common. The West Indian powderpost termite has been recorded in seven SC counties, coastal and Upstate, but only inside buildings.
They're relatively uncommon, according to NC State Extension. The main termite problem in North Carolina is subterranean termites. Pellet piles in NC homes often turn out to be rodent droppings.
Virginia Tech says drywood termites are very uncommon in Virginia, though they've been found in a few locations, usually in furniture. Eastern subterranean termites are Virginia's most common termite.
Clemson lists Formosan subterranean termites as established in 16 SC counties: Aiken, Bamberg, Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, Jasper, Lexington, Orangeburg, Pickens, Richland, Sumter and York. They were introduced at Charleston in the mid-1950s.
In North Carolina, Formosan termites were first found in Brunswick County in 1992 and are established only in the coastal southeast. In Virginia, they were confirmed at a single Norfolk property in 2022, which is a detection, not an established population.
Native subterranean termites swarm in the daytime from late winter into September or October, often on warm days after rain (NC State). Formosan termites swarm in the evening from mid-May to July and are attracted to lights (Clemson).
No. Drywood termite colonies never contact the soil, so soil treatments and bait stations don't reach them. Clemson lists wood removal, insecticide injection into galleries, freezing small items, or whole-structure fumigation.
Clemson describes drywood termite pellets as about 1/16 inch long, black, cream-colored or a mix, with a salt-and-pepper appearance, piled like tiny stones below the infested wood.
Subterranean termites, especially the Formosan subterranean termite where it's established. Formosan colonies can reach millions of termites, far more than native subterranean colonies.
Photo credits: USGS Native Bee Inventory and Monitoring Lab, public domain; Scott Bauer, USDA Agricultural Research Service, public domain; NY State IPM Program at Cornell University, CC BY 2.0; via Wikimedia Commons.