Drywood Termites in California: A Hidden Threat to Your Home
The short answer: Drywood termites are wood-destroying insects that live entirely inside wood without needing soil contact. Unlike subterranean termites, they nest in dry wood like attic framing, door frames, and roof timbers. These sneaky pests can go undetected for years while slowly damaging your home's structure. The most visible sign is small piles of fecal pellets that look like tiny grains of sand, pushed out through small holes in infested wood.
What Are Drywood Termites?
Drywood termites (family Kalotermitidae) establish colonies entirely within wood structures. They're fundamentally different from subterranean termites in one key way: no soil contact needed.
These termites get all the moisture they need from the wood itself. This lets them infest areas that subterranean termites can't reach—think attic framing, roof supports, and second-story window frames.
In California, drywood termites are found primarily along the Pacific coast and in parts of the Central Valley. The University of California Integrated Pest Management program lists drywood termites among the most economically important structural pests in coastal California.
Drywood termites form smaller colonies—typically fewer than 1,000 individuals compared to tens of thousands for subterranean termites. But multiple colonies can infest a single home, and they can take years to detect because they work slowly and silently inside wood.
What Do Drywood Termites Look Like?
Most homeowners never see drywood termites because they live hidden inside wood. The exception is during swarming season when winged reproductives emerge to start new colonies.
Swarmer Identification:
- Size: 3/8 to 1/2 inch long including wings
- Color: Pale yellowish-brown to dark brown
- Wings: Four equal-length wings with prominent veins, milky or smoky appearance
- Body shape: Thick waist—no "pinched" waist like ants
Swarmers typically appear during late summer and fall in California on warm, sunny days. They're attracted to light and often found near windows. After a brief flight, they shed their wings and pair up to start new colonies.
Where Do Drywood Termites Attack Your Home?
Drywood termites can infest any wood in your home, but they show preferences based on temperature and accessibility.
- Attic framing and rafters: Termites find cooler spots in ceiling joists cooled by air conditioning below
- Roof structures: Exposed roof timbers, sheathing, and wooden shingles
- Window and door frames: Protected joints and crevices around trim and molding
- Eaves and overhangs: Exposed wood edges and fascia boards
- Wood siding: Particularly where boards meet or overlap
They prefer unpainted or unsealed wood. Swarmers typically enter through cracks, joints, or end grain in wood.
How Do You Know If You Have Drywood Termites?
Drywood termites are sneaky. They don't build mud tubes like subterranean termites, and they work entirely inside wood. Most infestations go unnoticed for years.
Primary Warning Signs:
1. Fecal Pellets (Frass)
This is the most common sign. Drywood termites create small "kick-out holes" in wood and push out fecal pellets. Look for hard, six-sided pellets about 1mm long, uniform in size and shape (like tiny grains of sand), in colors from tan to dark brown. You'll find piles on windowsills, floors, or furniture below infested wood.
2. Kick-Out Holes
Small, round holes about 1-2mm in diameter in wood surfaces. These are temporary openings termites create to expel pellets.
3. Swarmers or Shed Wings
During late summer and fall, reproductive termites swarm to start new colonies. Finding winged termites indoors or piles of discarded wings near windows indicates an active infestation.
4. Damaged Wood
If you can access infested wood during repairs, you'll see smooth-walled galleries, chambers connected by tunnels, hollow-sounding wood when tapped, and cross-grain feeding patterns.
How Are Drywood Termites Treated?
Treatment options range from localized spot treatments to whole-structure fumigation.
Whole-Structure Fumigation
For widespread infestations or inaccessible areas, fumigation is most effective. The process involves covering the structure with a sealed tent, introducing sulfuryl fluoride gas that penetrates all wood, maintaining treatment for 16-72 hours, then aerating before re-entry. Fumigation eliminates all drywood termite colonies in the structure, regardless of location.
Localized Spot Treatments
For isolated infestations, spot treatments include wood injection (drilling and injecting termiticide), heat treatment (heating wood to 120°F+ for 33+ minutes), freezing with liquid nitrogen, or electrocution. Spot treatments work well for small infestations but require accurate location of all colonies.
Prevention
Reduce risk by sealing cracks and joints in exposed wood, painting or staining all exposed surfaces, installing screens on attic vents, removing wood debris from around your home, and scheduling regular professional inspections.
When Should You Call a Professional?
Drywood termite control is not a DIY project. Professional help is essential because detection requires specialized training, fumigation requires licensed applicators, homeowners often misdiagnose pellets as sawdust, and treating one colony may leave others untouched.
A professional termite inspection includes visual examination of all accessible areas, sounding wood to detect hollow areas, attic and crawl space inspection, microscopic examination of fecal pellets, and a written report with treatment recommendations.
Need a termite inspection? Call us at (800) 882-0374 or schedule your inspection online.
💡 Clark's Expert Insight
"I've inspected thousands of California homes for drywood termites, and I've learned to look where homeowners never think to check. One of my go-to spots? Inside walk-in closets with wood shelving or in bedroom door frames right above the hinges. Swarmers are attracted to light, so they land on windows, then crawl into nearby cracks. Years later, you find pellets in a closet corner or on a door hinge. If you spot even a tiny pile of pellets, call for an inspection immediately—you're probably seeing just one colony out of several in your home."
Frequently Asked Questions About Drywood Termites
How long does it take drywood termites to damage a home?
A: Drywood termite colonies develop slowly, taking 3-4 years to mature. Because colonies are small (fewer than 1,000 termites), structural damage typically takes 5-10 years to become significant. Multiple colonies in one home can speed things up.
Can I treat drywood termites myself?
A: DIY drywood termite treatment is generally ineffective because you can't see where termites are located inside wood. Professional fumigation or localized treatment by licensed applicators is the only reliable way to eliminate drywood termites.
What's the difference between drywood and subterranean termite damage?
A: Drywood termites create smooth-walled galleries free of soil or mud and produce fecal pellets. Subterranean termites pack galleries with soil or mud and build mud shelter tubes.
How much does drywood termite treatment cost?
A: Whole-structure fumigation for an average California home typically ranges from $1,200 to $2,500 or more. Localized spot treatments cost $300 to $800 per treatment area.
Do drywood termites swarm every year?
A: Mature drywood termite colonies (3+ years old) typically produce swarmers annually during late summer through fall in California. However, swarming flights are brief and occur on specific days.
Will drywood termites come back after fumigation?
A: Fumigation eliminates all existing colonies but provides no residual protection. Swarmers from neighboring properties can start new colonies after fumigation. Prevention measures and annual inspections are important.
Are drywood termites active year-round in California?
A: Yes, drywood termites are active year-round inside California homes where temperatures remain moderate. Swarming activity is seasonal, concentrated in late summer and fall.
Can drywood termites spread from one house to another?
A: Yes, during swarming season winged reproductives fly from established colonies to find new wood. They can travel several blocks and are attracted to light.
What should I do if I find termite pellets?
A: Don't clean them up immediately. Take photos, note whether the pile is fresh or old, and schedule a professional termite inspection as soon as possible.
Can I prevent drywood termites with termite bait stations?
A: No, termite bait stations only work for subterranean termites. Drywood termites never leave the wood they infest. Prevention requires sealing entry points and regular inspections.