Drywood termites are responsible for millions of dollars in structural damage across San Diego County every year. Unlike subterranean termites, which live underground and travel through mud tubes, drywood termites live inside the wood they're eating — which makes them harder to spot until the damage is already done.
Here are the five signs every San Diego homeowner should know.
1. Frass (Termite Droppings)
Drywood termites push their fecal pellets out of small kick-out holes in the wood. These pellets are tiny — about 1mm long — and look like fine sawdust or coffee grounds. You'll often find small piles of them on windowsills, floors, or countertops directly below infested wood. Unlike sawdust, termite frass is uniform in size and has a hexagonal shape when viewed under magnification.
2. Hollow-Sounding Wood
Tap along your baseboards, door frames, and wood trim with your knuckle. Solid wood produces a dense thud. Wood that's been hollowed out by termites produces a papery, hollow sound. This is one of the fastest DIY tests you can do — and one of the most reliable.
3. Discarded Wings Near Windows and Doors
Drywood termites swarm to start new colonies, typically in late summer and early fall in San Diego. After a swarm, the reproductives drop their wings — you'll find small, translucent wings clustered near light sources, windowsills, and door frames. Finding wings indoors almost always means the colony is already inside your structure.
4. Blistered or Bubbling Paint
As termites tunnel through wood just beneath a painted surface, the wood weakens and the paint above it can blister or bubble. This is often mistaken for water damage. If you see bubbling paint with no obvious moisture source, have the wood behind it inspected.
5. Visible Galleries in Exposed Wood
In attics, crawl spaces, or during a remodel when walls are open, you may see the tunnels (galleries) termites have carved through the wood grain. Drywood termite galleries are smooth and clean — they don't contain soil like subterranean galleries do.
What To Do If You Find These Signs
The good news: drywood termites are treatable, and not every infestation requires a full fumigation. Localized infestations caught early can often be handled with a spot treatment — a faster, cheaper, and less disruptive option. The key is getting an inspection before the colony spreads.
Contact DePests for a free termite inspection — we'll tell you honestly what you're dealing with and which treatment makes sense for your situation.