Termites in Santa Rosa: Swarm Season, Warning Signs, and What to Do Next
Short answer: Three termites damage homes here. Western subterranean termites swarm on sunny days right after the first fall rains, and again in spring. Western drywood termites fly during the day in summer and fall. Pacific dampwood termites show up where wood stays wet. Watch for mud tubes, small pellet piles, dropped wings, and hollow-sounding wood. A licensed inspection tells you which kind you have, and that answer decides the treatment.
Sonoma County gives termites almost everything they want. Wet winters. Dry summers. A lot of wood-framed homes built before 1980. Sprinklers running against foundations six months a year.
If your house is near Railroad Square, the West End, the McDonald Avenue historic district, or the Junior College neighborhood, there is a good chance it sits on a raised foundation with a crawl space under it. That setup is exactly what western subterranean termites look for.
Which termites live in Sonoma County?
Three species cause the damage here, and they behave very differently. Treating the wrong one wastes money and leaves the colony alive.
| Species | Where it nests | What you see | When it swarms here |
|---|---|---|---|
| Western subterranean Reticulitermes hesperus | Underground, linked to your house by mud tubes | Pencil-thin mud tubes on foundation walls and crawl space posts | Sunny days after the first fall rains, and again in spring |
| Western drywood Incisitermes minor | Inside dry, solid wood. No soil contact needed. | Small piles of six-sided pellets under tiny holes in the wood | Daytime flights in summer and fall |
| Pacific dampwood Zootermopsis species | Wood with a water problem, like a leaky deck or a rotting post | The biggest swarmers of the three. Damage always traces back to water. | Late summer into fall, usually near sunset, drawn to lights |
Subterranean termites do the most damage of any termite in California. Western drywood termites come second. Dampwood termites cause the least structural harm, but finding them still matters. They point to a leak or rot problem you need to fix.
When do termites swarm in Santa Rosa?
A swarm is a group of winged termites leaving the nest to start new colonies. Seeing one does not mean your problem just started. It means a colony nearby is mature, often several years old.
Here is how the year runs in the North Bay:
- October to December. This is the big one. Western subterranean termites swarm on calm, sunny days right after the first heavy fall rains. In the Bay Area, colonies across a whole neighborhood can fly on the same afternoon.
- February to May. A second subterranean window, again on warm days after rain.
- June to October. Western drywood termites fly during daylight hours. Pacific dampwood termites come out near dusk and head for porch lights.
Andrew Sutherland, the University of California's urban pest management advisor for the San Francisco Bay Area, has told news outlets that a single mature colony can send out hundreds of swarmers, and that dozens of colonies in one area can emerge on the same day. His rule for when to worry is simple. If termites are coming out of the ground or out of wood within a few feet of your house, get it inspected.
If you see a swarm, do not spray it. Take a photo of the exact spot the termites are coming out of, whether that is a crack in the slab, a weep hole, a window frame, or a fence post. Then catch a few in a sealed jar or bag. That one detail tells an inspector where to start and can save an hour on the inspection.
Five signs Santa Rosa homeowners spot first
- Mud tubes. Thin dirt tunnels running up foundation walls, posts, or pipe openings in the crawl space. These belong to subterranean termites, and they mean active traffic between the soil and your framing.
- Pellet piles. Small mounds of hard, six-sided pellets on windowsills, in the garage, or on the floor under eaves. This is drywood termite waste getting pushed out of the wood. People often mistake it for sawdust or coffee grounds.
- Dropped wings. Piles of matching clear wings on sills, in cobwebs, or around light fixtures. You usually find them after a rain in fall or spring.
- Hollow or blistered wood. Tap on door frames, baseboards, window headers, and eaves. Paint that looks rippled over solid wood is a classic drywood sign.
- Sticking doors and soft trim. Check the shady, watered side of the house first. Moisture and termites travel together.
Most of these signs hide in places homeowners rarely go: the crawl space, the attic, behind boxes in the garage. That is why so much California termite damage gets discovered during a home sale instead of by the person who has lived there for 15 years.
Why Santa Rosa homes are at higher risk
- Older houses. Neighborhoods near downtown went up before builders used modern termite detailing. Siding sits close to the ground and framing under the house is often untreated.
- Raised foundations. A vented crawl space over damp soil is a highway for subterranean termites. It is also a spot most homeowners never check.
- Sprinklers and landscaping. Overspray on siding, planter boxes built against the wall, and mulch piled up to the stucco all create the damp wood termites and rot fungus need.
- Wet winters, hot summers. Rain saturates soil and framing. Then summer heat triggers drywood swarms. Sonoma County gets hit both ways in the same year.
- Rebuilds and additions. New work next to an older house means fresh untreated lumber, stacked materials, and buried form boards. All of it is food sitting in contact with soil.
Buying or selling? What Section 1 and Section 2 mean
In California, a termite inspection produces a Wood Destroying Pests and Organisms report, usually called a WDO report. It is written by an inspector licensed through the California Structural Pest Control Board, filed with the Board, and available as public record.
Findings get sorted into two buckets, and the difference decides whether your escrow closes on time.
- Section 1 covers active problems. Live termites, active fungus or dry rot, and damage that already happened. Lenders usually require Section 1 items to be fixed, with a clearance issued, before they fund the loan.
- Section 2 covers conditions that invite trouble later. Wood touching soil, bad drainage, plumbing leaks, wood scraps under the house. Nothing is active yet. These get disclosed and negotiated, and they rarely block a sale. Leave them alone long enough, though, and they turn into Section 1 items.
Timing matters more than most buyers expect. A clearance is generally treated as current for about 90 days. Treatment plus a re-inspection takes days, not hours. Order the inspection in the first week of escrow, not the last. As for who pays, that gets negotiated in the purchase agreement. State law does not assign it.
Clark is a licensed operator with the Structural Pest Control Board. You can see what our report covers on our termite inspection page. Note that inspections for real estate transactions may be subject to a fee.
How treatment gets chosen
The species and the spread of the infestation decide the method. That is why inspection comes first.
Subterranean termites
The colony and its queens live below ground, so whole-house methods like fumigation or heat never reach them. Control means treating the soil around and under the house with a termiticide, treating nests through their own mud tubes, or installing bait and monitoring stations. Fixing the moisture and the wood-to-soil contact that fed the colony is part of the work, not an add-on.
Drywood termites
You have two paths, and the choice comes down to how far the infestation has spread.
- Local treatment works when activity sits in a few spots you can reach and identify, like one window header or a section of eave framing.
- Structural fumigation makes sense when colonies are scattered through framing nobody can reach. This is common in older homes with several separate pockets of activity. Fumigation reaches every void in the house at once. You have to move out for a set period and follow the prep checklist closely.
Dampwood termites
Fix the water and replace the ruined wood. Repairing the roof, deck, gutter, or pipe leak is the real treatment.
After treatment
Treatment kills termites. It does not put strength back into damaged wood. Weakened framing, subfloor, and trim need termite damage repair.
A treated house in Sonoma County is still a house in Sonoma County, so monitoring keeps working after the crew leaves. Term Alert® 365 catches the next colony while it is still cheap to handle. If you want general pest pressure covered at the same time, pair it with Year-Round Pest-Away®.
A prevention checklist for Sonoma County homes
- Keep soil, bark, and mulch at least 6 inches below your siding. Never pile it against the foundation.
- Point sprinkler heads away from the house. Overspray on wood siding is the most common problem written up on local reports.
- Fix roof, gutter, deck, and plumbing leaks right away. Wood that stays wet draws both rot and termites.
- Store firewood and lumber off the ground and away from the house. Not against the garage wall.
- Clear wood debris out of the crawl space, including form boards, stumps, buried scraps, and cardboard.
- Keep crawl space and attic vents open and screened so the space can dry out.
- Seal foundation cracks and gaps where pipes and wires enter.
- Get a professional inspection every one to three years, and before you list or buy.
When to call a professional
Call if you have seen a swarm on your property, found mud tubes or pellet piles, tapped on trim that sounds hollow, or opened escrow on a Sonoma County home.
Store-bought sprays will not reach a subterranean colony under your slab or drywood termites tunneling inside a header. They knock down what you can see while the colony keeps eating.
Clark Pest Control has served California and Nevada homes since 1950 and holds QualityPro and GreenPro certification. Our Santa Rosa branch covers Santa Rosa, Windsor, Healdsburg, Sebastopol, Sonoma, Petaluma, Rohnert Park, Cotati, Cloverdale, and Guerneville, plus parts of Marin and Napa counties.
Call 1-800-882-0374 or request your free termite inspection.
*Free inspection excludes real estate transactions, which may be subject to a fee.
Frequently Asked Questions About Termites in Santa Rosa
How do I tell termite swarmers from flying ants?
Look at the waist, the antennae, and the wings. Termites have a straight, thick waist, straight antennae, and four wings of equal length. Flying ants have a pinched waist, bent antennae, and front wings longer than the back pair. Termite wings also snap off easily, so a pile of loose wings on a windowsill points to termites.
I saw termites swarm in my yard, not my house. Should I worry?
Not always. Most soil around a home holds buried wood, like old roots, stumps, and fence posts. A colony feeding on that can swarm without ever touching your house. What matters is where the termites came out. If they emerged from a foundation crack, a wall, a window frame, or a porch, get an inspection.
What time of year should I schedule a termite inspection in Sonoma County?
Any time works, since mud tubes, pellets, and damage stay visible year round. Early fall is a smart time to book in Santa Rosa. It puts you ahead of the swarm that follows the first rains, and the crawl space is still dry enough for a good look underneath.
Does homeowners insurance cover termite damage?
Almost never. Insurers treat termite damage as a maintenance issue you could have prevented, not a sudden accident, so the repair bill usually lands on the homeowner. That is the strongest money argument for regular inspections. Catching activity early costs far less than replacing framing.
What does a Section 1 clearance cost and how long does it take?
It depends on what the report found. Treating one window header is a very different job from fumigating a house or replacing a subfloor. Timing is easier to predict. Plan on treatment plus a re-inspection taking several days, and remember a clearance is usually good for about 90 days. Clark gives you a written estimate after the inspection so you know both numbers before work starts. Note that inspections for real estate transactions may be subject to a fee.
Do I have to leave my house for termite treatment?
Only for whole-house fumigation. That one requires you to move out for a set period and follow a prep checklist, which includes bagging or removing food, medicine, and plants, plus arranging care for pets. Local treatments, soil treatments, and bait station installs do not require you to leave.
Can I treat termites myself?
Not effectively, and not in California. Subterranean colonies live underground where store products cannot reach them, and drywood termites tunnel deep inside framing. On top of that, only a licensed operator can issue the WDO report and clearance that lenders and escrow companies ask for. Retail sprays may kill the termites you can see while the colony keeps working.
How often should a Santa Rosa home be inspected for termites?
Every one to three years for most homes. Go annually if your house is older, sits on a raised foundation, has had termites before, or has a known moisture problem. Always inspect before you list or buy, since escrow is the most expensive time to find a Section 1 item.
Written by Clark Pest Control Technical Services. Clark has protected California and Nevada homes and businesses since 1950 and is licensed through the California Structural Pest Control Board.
Last updated: August 2026. Sources: University of California Statewide IPM Program, Pest Notes: Subterranean and Other Termites (UC ANR Publication 7415) and Pest Notes: Drywood Termites (UC ANR Publication 7440); California Structural Pest Control Board.