Drywood Termite Treatment & Control Options
Drywood termites live inside the wood they infest. They do not need the soil connection that subterranean termites rely on. That changes the treatment decision completely: the key question is whether the infestation is truly localized or whether hidden colonies could be present elsewhere in the structure.
The treatment route starts with the termite type
Drywood termites live directly in relatively dry wood. They do not need to travel back to soil. Subterranean termites do. That difference matters because a soil barrier designed for subterranean termites does not automatically solve a drywood termite colony sealed inside a roof beam, wall framing, door, or piece of furniture.
| Feature | Drywood termites | Subterranean termites |
|---|---|---|
| Where the colony lives | Inside the wood or wood product being infested | Primarily in soil, with workers traveling to wood for food |
| Soil contact required | No | Yes, directly or through shelter tubes / connected pathways |
| Common visible clue | Hard fecal pellets, swarmers, wings, small kick-out holes, localized wood damage | Mud tubes, soil-connected activity, swarmers, hidden wood damage |
| Main treatment question | Is the infestation localized, or could colonies be hidden in multiple areas? | How are termites moving between soil and the structure? |
| Typical control categories | Whole-structure fumigation, whole-structure heat, or localized/spot treatment | Soil-applied termiticide, bait systems, wood treatment, or combinations |
Government references: California Structural Pest Control Board — Termites Fact Sheet · USDA Forest Products Laboratory — Wood Handbook, Biodeterioration of Wood
Pellets, wings, and damaged wood tell different parts of the story
| Evidence | What it can indicate | Why inspection still matters |
|---|---|---|
| Small hard fecal pellets below wood | Drywood termites push waste pellets out of galleries through small openings | Pellets can help locate activity, but one pile does not prove the infestation is limited to that single spot |
| Discarded wings or swarmers | A mature colony may have produced reproductive termites | The entry/exit point can be far from the main area of damage |
| Wood that sounds hollow or breaks along internal galleries | Termites may have consumed wood from inside while leaving an outer surface intact | The visible damage may not show the full extent of hidden galleries |
| One obvious damaged board or trim piece | The infestation may be localized | Hidden colonies elsewhere must be considered before choosing spot treatment |
| Evidence in multiple rooms or roof areas | More than one colony or a broad infestation may be present | Whole-structure control may deserve consideration because localized treatment depends on finding each infestation |
Government reference: USDA Forest Products Laboratory — Wood Handbook, drywood-termite prevention and control discussion
The real decision is how confident you are about the infestation boundary
California's Structural Pest Control Board publishes some of the clearest government consumer guidance on drywood termite treatment. It distinguishes whole-structure eradication from localized treatment: fumigation and whole-structure heat are intended to treat the entire structure, while spot methods treat only the areas where termites have been located.
Whole-Structure Fumigation
Gas penetrates throughout the enclosed structure.
- Designed to reach drywood termites in accessible and hidden wood throughout the fumigated space
- Does not depend on locating every colony before treatment
- Requires substantial preparation and temporary vacancy
- Provides eradication at the time of treatment but no lasting residual barrier against future drywood-termite entry
Whole-Structure Heat
Raises temperatures in structural wood to lethal levels.
- Non-fumigant whole-structure approach
- Requires careful temperature monitoring throughout target wood
- Heat-sensitive belongings or building materials may need special handling
- Effectiveness depends on every infested area reaching the required temperature for long enough
Localized / Spot Treatment
Targets identified colonies or infested wood.
- Can include labeled liquid, dust, foam, heat, microwave, or other approved local methods
- Can make sense when the infestation is truly limited and clearly located
- Usually involves less whole-house disruption
- Does not eliminate colonies that were missed elsewhere in the structure
| Decision factor | Whole-structure fumigation | Whole-structure heat | Localized treatment |
|---|---|---|---|
| Need to find every colony first? | No | No, but all target areas must reach the required temperature | Yes — success depends heavily on locating the infestation |
| Hidden-infestation coverage | Strong whole-structure reach when properly performed | Whole-structure approach, limited by heat penetration and monitoring | Only the treated/localized areas |
| Household disruption | High; occupants must leave during fumigation and until clearance | High to moderate; heat-sensitive items and occupants must be managed | Usually lower |
| Residual future protection | No lasting fumigant residue | No continuing residual barrier from heat alone | Depends on the specific labeled product and application |
| Best fit | Broad, hidden, multiple, or hard-to-map infestations | Properties suitable for whole-structure thermal treatment | Limited, accessible, well-defined infestations |
Government references: California Structural Pest Control Board — Termites Fact Sheet · California Structural Pest Control Board — Fumigation FAQ
Structural fumigation is a specialized treatment with strict re-entry rules
EPA says sulfuryl fluoride is the only fumigant currently registered for residential structural use. It is a restricted-use pesticide, so it can only be applied by a certified applicator or someone under that applicator's direct supervision.
Prepare the structure
Follow the fumigator's written preparation instructions for people, pets, food, medicines, plants, and other items.
Seal / tent
The structure is enclosed so fumigant can be held at the required concentration.
Fumigation
Only trained, authorized personnel handle sulfuryl fluoride and the fumigation process.
Aeration
After treatment, the structure is aired out according to label and safety requirements.
Clearance
EPA requires the structure to be tested before re-entry; clearance is based on measured fumigant concentration.
Do not re-enter because the tent came off
EPA states that a residential structure is considered cleared only after the certified operator or a person under their supervision verifies sulfuryl fluoride has dissipated to 1 part per million or less in the breathing zones of each room using an appropriate clearance device.
Government references: U.S. EPA — Sulfuryl Fluoride · U.S. EPA — Sulfuryl Fluoride Clearance Devices
Heat can work — but the wood temperature, not the thermostat, is what matters
Drywood termites live inside wood galleries. Successful thermal control depends on heat reaching lethal temperatures inside those wood members, not merely warming the room. Government and USDA research both emphasize temperature and exposure time at the termite's location.
| Heat-treatment issue | Why it matters | What to ask the provider |
|---|---|---|
| Core wood temperature | Termites inside framing are protected by the wood surrounding them | How are temperatures monitored inside target wood, not just in the room air? |
| Cold spots | Dense construction, masonry, shaded zones, or airflow patterns can slow heat penetration | How will cold spots be identified and monitored? |
| Heat-sensitive belongings | Some contents can be damaged by high temperatures | What needs to be removed, protected, or handled separately? |
| Reinfestation | Heat kills termites present during treatment but does not create a lasting barrier against future drywood-termite entry | What inspection and prevention plan follows treatment? |
Government references: USDA Agricultural Research Service — Heat Tolerance of Structure-Infesting Drywood Termites · California Department of Pesticide Regulation — 2026 structural fumigation alternatives report
Spot treatment works only where the infestation has actually been found
Localized treatment can be practical when evidence points to a small, accessible infestation. The limitation is straightforward: treatment cannot kill a hidden colony that was never discovered and never treated.
Liquid, foam, or dust
Labeled products may be injected into termite galleries or infested wood when the colony location can be targeted.
Thermal spot treatment
Heat may be applied to a defined area if target wood can be heated thoroughly enough to kill termites inside.
Replace heavily damaged wood
USDA wood guidance notes that badly damaged infested wood may need replacement, with pest control and repair treated as separate decisions.
| Spot-treatment strength | Spot-treatment limitation |
|---|---|
| Less whole-house disruption | Depends heavily on accurate colony location |
| Can target accessible damaged wood directly | Concealed colonies outside the treated zone can survive |
| Can be useful when evidence is truly isolated | May require repeated inspection or additional treatment if new evidence appears |
| Can preserve portions of a structure that do not need whole-structure work | Should not be presented as whole-house eradication unless the treatment actually covers the whole structure |
Government references: California Structural Pest Control Board — local vs whole-structure treatment · California Structural Pest Control Board — Field Evaluations of Localized Treatments
Six questions to ask before agreeing to drywood-termite work
How was drywood termite activity confirmed?
Ask what evidence distinguishes drywood termites from subterranean termites, ants, beetles, or old damage.
How widespread is the infestation?
One pellet pile is different from evidence in several rooms, roof areas, or structural zones.
Why whole-structure or why local?
The provider should explain what makes the infestation suitable — or unsuitable — for spot treatment.
What will treatment not reach?
For localized work, ask directly which hidden or inaccessible areas will remain untreated.
What follow-up is included?
Ask about reinspection, new pellet piles, swarm activity, retreatment terms, and any service agreement or warranty.
Who is licensed to perform the work?
Licensing requirements vary by state. Structural fumigation also involves restricted-use pesticide rules and certified applicator requirements.
Old pellets can stay behind — new pellets matter more
| What you notice after treatment | How to interpret it | Reasonable next step |
|---|---|---|
| Old pellet piles remain | Pellets do not disappear automatically when termites are controlled | Clean documented areas so new pellet accumulation is easier to recognize |
| Fresh pellets appear again | New material can indicate continuing or renewed activity | Photograph the location and contact the provider for reinspection |
| New swarmers or discarded wings | Reproductive activity may indicate a colony is still present or a new infestation has developed | Request identification and inspection rather than assuming treatment failure from appearance alone |
| Damaged wood remains weak | Killing termites does not restore wood strength | Have significant structural damage evaluated and repaired separately |
| No new evidence appears | Treatment may have controlled the known infestation | Continue periodic inspection because drywood termites can reinfest structures in the future |
Questions homeowners ask about drywood termite control
Do drywood termites need soil?
No. Drywood termites live inside the wood they infest and can complete their colony life cycle without a soil connection. That is one of the biggest differences from subterranean termites.
What do drywood termite droppings look like?
Drywood termites produce small, hard fecal pellets that can collect below infested wood. Pellet piles are useful evidence, but the colony can be hidden inside wood above or nearby.
Is fumigation the only way to treat drywood termites?
No. Government consumer guidance recognizes whole-structure fumigation, whole-structure heat, and localized treatment. The right choice depends on how widespread and accurately located the infestation is.
When is spot treatment reasonable?
Spot treatment makes the most sense when the infestation is limited, accessible, and confidently located. Its weakness is that hidden colonies outside the treated area can survive.
Does fumigation prevent drywood termites from coming back?
No. Fumigation kills termites present during treatment but leaves no lasting protective residue in the wood. Future reinfestation is still possible.
How do I know when it is safe to go back inside after fumigation?
Do not rely on tent removal alone. EPA requires clearance testing. For sulfuryl fluoride residential fumigation, the structure must be verified at 1 ppm or less in breathing zones before re-entry.
Can heat treatment replace fumigation?
Whole-structure heat can be an alternative in suitable structures, but it must deliver lethal temperatures throughout the infested wood. Cold spots and heat-sensitive materials can affect treatment planning.
Should I repair damaged wood before or after termite treatment?
That depends on access and the treatment plan. Termite control and structural repair are separate jobs. Coordinate with the pest-control provider so repair work does not hide evidence or interfere with treatment.
Use the right termite page for the problem you actually have
WDI / Termite Inspection
Start here if the termite species or current activity has not been confirmed.
Review inspection guidance →Subterranean Termite Treatment
Use this separate guide when termites are soil-connected rather than drywood termites.
Compare subterranean treatment options →How It Works
See how homeowners can connect with independent participating pest-control providers.
See how the connection process works →Trusted resources behind this drywood-termite guide
The treatment and safety information on this page is grounded in U.S. federal and state government resources. Treatment availability, pesticide rules, licensing, preparation instructions, and re-entry requirements still depend on the specific state, product label, applicator, and property.
- U.S. Environmental Protection Agency: Sulfuryl Fluoride — residential structural fumigation information
- U.S. Environmental Protection Agency: Sulfuryl Fluoride Clearance Devices and residential re-entry level
- California Structural Pest Control Board: Termites Fact Sheet — whole-structure and local treatment
- California Structural Pest Control Board: Structural Fumigation FAQ
- USDA Forest Products Laboratory: Wood Handbook — Biodeterioration of Wood
- USDA Agricultural Research Service: Heat Tolerance of Structure-Infesting Drywood Termites
- California Department of Pesticide Regulation: 2026 structural fumigation alternatives report
Need help with suspected or confirmed drywood termites?
Call to check whether an independent pest-control provider connection is available in your area. If the termite species or infestation extent is uncertain, ask about inspection before choosing between whole-structure and localized treatment.