Drywood Termites: Signs, Pellets and Treatment

Drywood termites skip the soil, the mud tubes and the foundation entirely. They fly in, move into a piece of dry wood and stay there for a decade. That makes them easy to miss, impossible to stop with a soil treatment, and surprisingly good at traveling inside your furniture.

By John Updated 6 min read
Sketch of a cutaway window frame showing drywood termite galleries inside the wood, with a small heap of pellets on the sill below
The whole colony fits inside the window frame. The pellets on the sill are the only part you're meant to see.

The short version

Drywood termites live entirely inside dry wood, such as framing, trim, furniture and attic lumber, with no contact with soil. Colonies are small, usually under 1,000 termites, but a building can hold many. Look for hard six-sided pellets, tiny kick-out holes, blistered wood surfaces and swarmers indoors. They're common in Florida, the Gulf Coast, California, Arizona and Hawaii.

On this page
  1. How drywood termites live
  2. The drywood termites that matter
  3. Drywood swarm months
  4. The signs, from most to least obvious
  5. Why they're hard to find
  6. Keeping them out
  7. Treatment in one table
  8. If you suspect drywood termites
  9. Questions

How drywood termites live

Most termites in the U.S. are subterranean. They nest in the soil and travel to wood through mud tubes, so treating the soil around a house can stop them. Drywood termites play a completely different game.

A pair of swarmers lands on a house, finds a crack or joint in dry wood and seals themselves in. Everything the colony needs comes from that wood and the surrounding air, so they never go outside again. UC IPM, which studies California's western drywood termite, says colonies usually hold fewer than 1,000 termites, tiny by subterranean standards.

What they lack in size they make up in time and numbers. UF/IFAS says West Indian drywood colonies mature at about five years and then produce swarmers every year for the rest of their lives, which can run past ten. Each swarm can seed new colonies in the same building. An old house in drywood country may hold dozens of separate colonies, each in its own board.

The drywood termites that matter

Three species do most of the structural damage in the U.S. Their ranges barely overlap, so where you live narrows it down.

Main U.S. drywood termites
Species Where Swarms Notes
Western drywood (Incisitermes minor) California, Arizona Warm, sunny days in summer and fall (UC IPM); June to August in Arizona UC calls it California's second most important termite pest
West Indian drywood (Cryptotermes brevis) Florida's coasts and many Florida cities, Hawaii, Gulf Coast pockets Mostly April to June, but possible any month (UF/IFAS) Lives only in structures and wooden objects; once nicknamed the "furniture termite"
Southeastern drywood (Incisitermes snyderi) Gulf Coast and coastal Southeast Late summer, at night (Texas A&M) The most common drywood termite in Texas

The full species list, with subterranean and dampwood termites, is in types of termites.

Drywood swarm months

Typical swarm months for the main drywood termites
Termite J F M A M J J A S O N D
Western drywood Warm, sunny afternoons some swarms peak peak some swarms
West Indian drywood Night, toward lights common peak common
Southeastern drywood Night, toward lights common peak

The signs, from most to least obvious

Pellets

The clue nearly everyone finds first: little heaps of hard, six-sided pellets under the wood the colony lives in. UF/IFAS notes they can be cream, red or black, and that the color doesn't tell you much. Reading a pellet pile, and the two-week test for whether it's still active, has its own guide: termite droppings but no termites.

Kick-out holes

Workers push pellets out through small holes, usually 1 to 2 millimeters across according to UF/IFAS, and then plug them. Where a hole sits high on a wall, pellets scatter in a loose circle instead of a neat pile.

Blistered or peeling surfaces

UF/IFAS lists blistering or peeling of thin surface wood or paint as a sign. The colony has eaten the wood right up to the surface and left a skin of paint over the gallery.

Swarmers and wings indoors

Drywood swarms are smaller than subterranean swarms, but they happen inside the house when the colony is inside the house. Wings on a sill in a room with no doors open is a strong hint.

What you won't see

No mud tubes, no soil in the damage, no trail from the ground. If you have mud tubes, you have subterranean termites, maybe in addition. See termite mud tubes.

For spotting drywood signs

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Why they're hard to find

UC IPM puts it plainly: drywood termites live deep in wood and are rarely seen except when swarming or during repairs, and finding hidden colonies can require removing wall coverings, paneling or stucco. Professionals sometimes add tools like detector dogs, acoustic sensors, borescopes and infrared cameras, though UC notes these are used infrequently and none is perfect.

That has a practical consequence. An inspection can confirm drywood termites in the places it can see, but it can rarely promise there are no other colonies. Keep that in mind when someone proposes treating "just this one window."

Keeping them out

Because drywood termites arrive by air, prevention is about closing the doors they fly in through.

  • Seal and screen. UF/IFAS recommends excluding swarmers with caulk or with mesh with openings of about 1 millimeter on vents and openings.
  • Paint and seal exposed wood. UC IPM lists barriers like screens and paint among preventive options. Bare, cracked wood is an invitation.
  • Treat attics and voids. UF/IFAS describes borate dust applied in attics and wall voids as a preventive step. A licensed company should do this, following the product label.
  • Use treated wood where it fits. UC notes pressure-treated wood is common in California but can fall short where it's been drilled, cut or leached by rain.

None of this helps against termites already inside. For that, you need an inspection and a treatment plan.

Treatment in one table

Treating drywood termites comes down to one question: can every colony be found and reached? Here's the short version. The full comparison is in drywood termite treatment.

Drywood termite treatment choices
Situation Usual approach Trade-off
One or two colonies, accessible Local treatment: injected termiticide, foam, local heat, or replacing the board Cheaper and you stay home, but hidden colonies are missed
Single apartment or room Room-level heat, which UF/IFAS says is usually used for rooms or apartments No residue; heat-sensitive items need care
Many colonies, or ones you can't reach Whole-structure fumigation (tenting) or whole-house heat Reaches everything, but leaves no protection behind
After any whole-house treatment Preventive measures above Stops new swarmers moving in

California's Structural Pest Control Board warns against any company claiming whole-house results from a local or spot treatment.

If you suspect drywood termites

Do

  • Photograph pellet piles and look straight above them for holes
  • Check attic framing, window frames and wooden furniture
  • Ask the inspector how many colonies they found, and where
  • Get two opinions before agreeing to tent the house
  • Inspect secondhand wooden furniture before it comes inside

Don't

  • Pay for a soil treatment to fix drywood termites
  • Fill holes with caulk and call it done
  • Assume one treated board means a termite-free house
  • Bring in an antique with fresh pellets underneath

Questions people ask

What are drywood termites?

Termites that live entirely inside dry wood with no contact with soil. Their colonies are small, usually under 1,000 termites, and they reveal themselves mainly through piles of six-sided pellets, tiny holes and indoor swarms.

Where are drywood termites found in the U.S.?

Mostly in warm, mild places: Florida, the Gulf Coast and coastal Southeast, southern California, Arizona and Hawaii. They can also travel in furniture and wooden goods to almost anywhere.

How do I know if I have drywood or subterranean termites?

Drywood termites leave hard pellet piles and no mud. Subterranean termites build mud tubes and leave soil in the wood they eat. If you find both, you may have both.

Can drywood termites spread from furniture to my house?

Yes. Swarmers from a colony in a piece of furniture can start new colonies in the house's wood. UF/IFAS says the West Indian drywood termite spreads mainly through people moving infested wooden articles.

Do I need to tent my house for drywood termites?

Not always. If an inspector can find and reach every colony, local treatment can work. Tenting or whole-house heat makes sense when colonies are widespread or hidden. Get more than one opinion before choosing.

Termites in your state

Sources