Drywood vs. Subterranean Termites in the Carolinas

A termite is a termite — until you try to treat it. The two termite types most active in South Carolina, North Carolina, and coastal Virginia require completely different treatments, and using the wrong approach will leave your home unprotected. Knowing which species you're dealing with is the single most important step before any treatment decision is made.

Here's a practical breakdown of how these two termites differ, what each one looks like in your home, and what getting rid of each one actually requires.

The Big Picture: Two Very Different Pests

Subterranean termites live underground. They need consistent soil contact to survive — soil provides the moisture that keeps their bodies from drying out — and they travel between the earth and your home through mud tubes they build themselves. They are by far the more common and destructive type throughout our region.

Drywood termites do not need soil at all. They live entirely inside the wood they eat, drawing just enough moisture from the wood fibers and humid air to survive. In our climate, this means they show up most often in coastal areas of South Carolina and Virginia — places where the combination of warm temperatures and high humidity lets drywood colonies persist year-round.

Subterranean Termites: What SC, NC & VA Homeowners Are Most Likely Facing

The Eastern Subterranean Termite (Reticulitermes flavipes) is the most widespread termite in North America and the species behind the vast majority of termite damage in the Carolinas and Virginia. In coastal South Carolina — particularly the Charleston and Beaufort areas — the Formosan Subterranean Termite (Coptotermes formosanus) is also present and is significantly more aggressive. Formosan colonies can number in the millions and consume wood several times faster than native subterranean species.

Where they attack: Subterranean termites focus on wood with soil contact or that can be reached through mud tubes — sill plates, floor joists, support beams, subflooring, and wood framing near the foundation. They work from the bottom up.

Signs of subterranean termites:

• Mud tubes: Pencil-width earthen tunnels running up your foundation walls, pier blocks, or through crawlspace walls. This is the most reliable field indicator. Break a tube open — if you see small creamy-white workers inside, the colony is active.
• Swarmer season: Eastern subterranean termites swarm on warm days following spring rains, typically February through May in SC and NC, slightly later in VA. You may find winged alates (swarmers) near windows, lights, or at the base of walls. Formosan termites typically swarm in the evening, May through June.
• Discarded wings: After swarming, termites shed their wings. Small piles of equal-sized wings near entry points — window sills, door frames, baseboards — are a warning sign.
• Hollow-sounding wood: Tap floor joists or baseboards along the foundation — a hollow drumlike sound can indicate galleries eaten through the wood interior.
• Damaged wood grain: Unlike carpenter ants, which push wood shavings out, subterranean termites pack galleries with soil and their own secretions. The wood will appear layered and honeycombed when cut open.

Drywood Termites: Less Common, But Worth Knowing

The West Indian Drywood Termite (Cryptotermes brevis) is the drywood species most often encountered in South Carolina and coastal Virginia. It's an introduced species and is most established in port cities — Charleston, Beaufort, Wilmington, Virginia Beach, and Norfolk.

Drywood termites infest wood directly — attic framing, hardwood floors, furniture, door frames, window frames, and even structural lumber. Unlike subterranean termites, they don't need any contact with the ground, which means a colony can be living entirely in your attic or inside finished wall framing with no sign at the foundation level.

Signs of drywood termites:

• Frass piles: The most distinctive sign. Drywood termites push their fecal pellets — called frass — out of small kick-out holes in infested wood. The pellets are tiny (about 1mm), six-sided, and look like coarse sawdust or coffee grounds. You'll find small piles of them below infested furniture legs, window frames, or on attic floors. This is the sign that separates drywood from every other termite type.
• No mud tubes: If you're seeing damage but no mud tubes anywhere on the foundation or walls, drywood termites are a real possibility.
• Kick-out holes: Tiny 1–2mm diameter holes in wood surfaces where frass is pushed out. They may be nearly invisible without close inspection.
• Swarmers: Drywood swarmers are slightly larger than Eastern subterranean swarmers, with darker reddish-brown bodies. They swarm in late summer and fall — August through November in SC — often at night and toward light sources.

Side-by-Side Comparison

Treatment: Why the Species Determines the Method

This is where getting the identification right really matters. The wrong treatment doesn't just fail — it wastes months while a colony keeps eating.

Subterranean termite treatments target the soil and colony:

• Liquid termiticide barriers (such as products containing fipronil) are applied to the soil around and beneath the foundation, creating a treated zone termites encounter as they travel. Non-repellent formulas allow termites to pass through the treatment zone and carry it back to the colony.
• Bait systems (such as the Sentricon system) use monitoring stations placed in the ground around the structure. When termites feed on bait, they carry an active ingredient back to the colony and share it with nestmates, eventually eliminating the colony.
• Both approaches work; bait systems are often preferred for their environmental profile and ongoing monitoring value.

Drywood termite treatments have to reach termites inside the wood:

• Structural fumigation (tenting) is the most thorough approach for widespread or multi-room drywood infestations. A gas fumigant permeates all wood in the structure and kills termites at every life stage. It requires vacating the home for 2–3 days.
• Spot treatments using orange oil (d-limonene), heat, microwave, or injectable foams can be effective for localized, confirmed drywood infestations. They avoid the inconvenience of fumigation but require accurate localization of the infested wood — which is why professional inspection matters.

Note that soil treatments and bait systems, which work well for subterranean termites, do nothing for drywood termites because drywood colonies never contact the soil. Treating for the wrong type won't protect your home.

What About Mixed Infestations?

In coastal SC and coastal VA, both types can be present simultaneously in the same structure. A professional inspection using moisture meters and acoustic devices can help confirm whether one or both species are active. This scenario is uncommon inland but worth noting for homeowners in the Charleston area, Myrtle Beach, and Hampton Roads markets.

What to Do If You Suspect Either Type

Don't wait. Subterranean termites in particular work fast — a well-established Formosan colony can cause significant structural damage within a single season. Even slower-moving drywood infestations get larger over time and become more expensive to treat.

• Document what you find: Take a photo of mud tubes, frass piles, swarmer wings, or damaged wood before disturbing them. Your technician will want to see the evidence.
• Don't break or clean mud tubes before your inspection: Active mud tubes confirm an ongoing infestation; removing them before an inspection can delay diagnosis.
• Request a full inspection, not just a spot check: Termites often damage areas that aren't immediately visible — crawlspaces, attic framing, wall voids. A thorough inspection includes all of these.

For more on what to look for before the inspection, see our guides on signs of a termite infestation and termite warning signs every homeowner should know.

If you're ready for a professional set of eyes on your home, our termite control team serves Charleston, Columbia, Greenville, Raleigh, and Hampton Roads — and we'll tell you exactly which species we find and what it takes to eliminate them. Request a free quote today.