Short answer: The clearest signs of drywood termites in a Riverside home are small piles of hard, six-sided pellets called frass, the pinhole-sized kick-out holes those pellets fall from, discarded wings on windowsills after a swarm, and wood that sounds hollow when you tap it. Frass confirms the species. Whether the colony is still alive takes one more step.
That pile is the most reliable evidence you will get, and it says more than anything else in the house. Here is what each sign looks like, how to tell termite pellets from sawdust, and the one test that separates an active colony from an old one.
What Are the Early Signs of Drywood Termites?
The early signs of drywood termites are pellets, holes, wings, blistered paint, and hollow wood, usually in that order of how often people notice them.
Frass pellets
Small piles of hard, dry, six-sided droppings below infested wood.
Kick-out holes
Pinhole openings the termites push those pellets through.
Discarded wings
Piles of identical translucent wings near windows and doors after a swarm.
Blistered paint
Rippled or cracked paint where a gallery runs just under the surface.
Hollow-sounding wood
A beam or door frame that sounds papery when you knock on it.
Drywood termites live entirely inside the wood they eat and never touch soil, which is why you almost never see the insect itself. According to the UC Statewide IPM Program, they are cryptic insects that live deep inside wood and are seldom seen except when they swarm. The evidence they leave behind is the whole game.
Frass Is the Sign That Confirms the Species
Frass is digested wood that termites push out of their galleries to keep the tunnels clear. UC IPM states that drywood termite fecal pellets have six hexagonal sides and that this shape is diagnostic for the species. No other household pest leaves that.
What a pile looks like in a real house:
- Size. Individual pellets run about the size of a coarse grain of sand or a poppy seed.
- Color. Anywhere from pale tan to nearly black, because the color matches the wood being eaten.
- Feel. Hard and dry. Roll a few between your fingers and they hold their shape.
- Shape of the pile. A small cone directly below the hole, or a scattered spray if the hole sits higher up a wall.
That is a real one from a Riverside job. Notice how the pellets run in a line rather than sitting in a single tidy cone, which is what happens when the galleries above are working along a length of beam instead of a single spot.
How to Tell Frass From Sawdust
Sawdust is irregular. Frass is uniform. That is the fastest way to separate them without a magnifier.
Wood shavings from drilling or from carpenter ants come out as ragged slivers of different sizes, and they crush into powder under your finger. Drywood termite pellets come out as thousands of near-identical capsules that stay solid when you press them. Drywall dust is a fine white powder with no granules in it at all.
UC IPM notes two other pests that get confused with drywood termites during identification: wood boring beetles and carpenter ants. It also flags dampwood termites, whose pellets are football shaped with rounded ends and lack the lengthwise ridges drywood pellets carry. If you are looking at a pile and cannot call it, that is a normal place to stop guessing.
Kick-Out Holes Are Where the Pile Comes From
Look directly above any pile of pellets and you will usually find the hole they came out of. UC IPM puts kick-out holes at less than two millimeters across, which is roughly the tip of a ballpoint pen.
They are easy to miss because they are tiny and because they turn up in places nobody inspects: the underside of a windowsill, the back edge of a door frame, a garage header, the seam where a patio cover meets the house. Finding the hole matters, because it marks the exact board that is infested rather than the general area.
Discarded Wings After a Swarm
Piles of identical, translucent wings near a window or a light fixture mean a mature colony released reproductives nearby. UC IPM reports that western drywood termite swarmers fly during daytime hours in summer and fall, which puts Riverside inside the window right now.
All four wings on a termite swarmer are the same length, which is the quickest way to separate them from flying ants. If you have swarmers and want to identify what you are holding before you call anyone, our guide to telling flying ants from termites walks through the differences.
Blistered Paint and Hollow-Sounding Wood
Drywood termites eat wood from the inside and leave the outer surface intact. When a gallery runs close to a painted surface, the paint above it ripples, bubbles, or cracks in a way that looks like water damage without any water source.
That is the same kind of wood after it was opened up. Everything packed into those channels was pellets and gallery, and none of it was visible from the outside until the board came apart.
Hollow sound works the same way. Knuckle a baseboard, a door frame, or an eave and listen for a papery, empty tone against the solid thud of good wood. The damage is usually well established by the time you can hear it.
How Do You Know If a Drywood Termite Infestation Is Active?
Clean up the pellets, mark the date, and check back in a few days. That is the method UC IPM recommends, and it is the single most useful thing you can do before anyone comes out.
The reason it matters: UC IPM states plainly that fecal pellets alone cannot tell you whether an infestation is currently active or how far it extends. Pellets from a colony that died years ago sit in a gallery until vibration shakes them loose, so an old pile and a new pile look identical.
Do it this way. Photograph the pile before you touch it. Sweep or vacuum it completely. Write the date on a piece of tape next to the spot. If new pellets appear over the next several days, something is alive in that wood. UC IPM adds one honest caveat, which is that normal building movement can shake old pellets loose too, so the test points you in a direction rather than settling it.
What it cannot tell you is how far the galleries run or how many separate colonies are in the structure. That takes moisture meters, sounding tools, and someone who has looked at a few thousand of these. It is what a Riverside termite inspection is for, and it starts at $125 for homes up to 2,000 square feet.
How Long Does It Take for Drywood Termites to Cause Damage?
Years, which is exactly why the damage is usually well along by the time anyone finds it. UC IPM describes drywood colonies as small, usually fewer than 1,000 individuals, widely dispersed, and slow to mature.
Two things follow from that. A single colony chews slowly, so finding frass this week does not mean your house is coming down next month. And a slow, hidden pest gets a long head start, so the first pile of pellets you notice is rarely the beginning of the problem. A structure can also carry several separate colonies at once in different boards, which is why an inspection covers the whole house instead of the one windowsill that got your attention.
Where Drywood Termites Turn Up in Riverside Homes
The western drywood termite is native to this part of California. UC IPM places it along the Pacific coast and inland through the Central Valley and the deserts of Southern California, which puts Riverside squarely in its home range rather than on the edge of it.
In a Riverside house, the wood they find first is usually the wood exposed to sun and weather:
- Fascia boards and exposed rafter tails
- Eaves and roof overhangs
- Attic framing
- Window and door frames, especially on south and west walls
- Garage headers and door trim
- Patio covers, pergolas, and wood trellises
Older neighborhoods carry more risk simply because they carry more exposed wood and more decades of opportunity. Newer stucco homes are not exempt, since the framing, the eaves, and the trim are still wood.
What to Do When You Find Frass
Do not spray it. UC IPM is direct on this point: the products used to control drywood termites are not sold to the public, and do-it-yourself treatment is not recommended because you cannot see the extent of what you are treating. A retail can reaches the surface, and the colony lives inside the board.
Professional work goes into the wood instead of onto it. Foam expands through the gallery network behind a frame or inside a void, which is the part a homeowner has no way to reach.
Do photograph the pile, run the sweep-and-check test, and note every other spot in the house where you have seen the same material. That list is genuinely useful to an inspector.
Then get the wood looked at. The inspection confirms the species, maps how far the galleries run, and settles which treatment the house actually needs, which ranges from a $495 local treatment up to full structure fumigation at $2,395 for homes up to 1,800 square feet. Our full breakdown of termite treatment costs in Riverside covers what moves each number.
If you are buying or selling, this becomes a paperwork question as well as a pest question, because most California sales need a wood-destroying organism report before escrow closes. Here is how we handle termite reports for real estate transactions.
Find out what is in the wood
A pile of pellets tells you the species. It does not tell you how much of the house is involved, and that is the part that decides what this costs you.
Schedule a termite inspection or call (951) 653-7964. Riverside and Moreno Valley offices, family owned since 2012, license PR 7461, Branch 2 and 3.
Drywood Termite Questions From Riverside Homeowners
What do drywood termite droppings look like?
They look like tiny grains of coarse sand or coffee grounds, hard and dry, in a range of colors from pale tan to almost black depending on the wood being eaten. Under magnification each pellet has six flat sides, and UC IPM treats that hexagonal shape as diagnostic for drywood termites. They pile up below a pinhole-sized opening in the wood.
Does finding frass mean the termites are still there?
Not on its own. UC IPM states that pellets alone cannot establish whether an infestation is active. Pellets from a colony treated years ago can still fall when the building moves. Clear the pile, note the date, and watch the spot for several days. New pellets point to live activity.
Can I treat drywood termites myself?
No, and UC IPM says so directly. The products that control drywood termites are not available to the general public, and the program advises against do-it-yourself treatment because the extent of an infestation is so hard to determine. Removing an infested board is the one exception, and that only helps when the colony is confined to that board.
What month do drywood termites swarm in Riverside?
Summer and fall, during daylight hours, according to UC IPM. That is when most Riverside homeowners see their first physical evidence, because the swarmers leave the wood and the wings turn up on windowsills and floors afterward. Activity inside the wood continues year round in this climate.
How are drywood termites different from subterranean termites?
Drywood termites live inside the wood and need no contact with soil. Subterranean termites live in the ground and build mud tubes to reach the structure. Riverside has both, and the difference decides the treatment entirely. Our Riverside termite control page covers how each species gets handled.
Does frass mean I need a tent?
Often it does not. Whether a house needs full structure fumigation depends on how far the galleries have spread and whether we can reach them directly, and the inspection is what answers that. Most Riverside homes we inspect never get tented.
