Before anyone can tell you what a treatment will cost, they have to establish
what is living in your house. The two species common in this area behave so
differently that almost nothing about the response is shared between them.
The good news: the signs they leave are distinct enough that you can often make
a reasonable guess before an inspector arrives.
The short answer
Small pellets that look like coarse sand or coffee grounds mean drywood
termites. Pencil-width tubes of dried mud running up a foundation wall mean
subterranean termites. Drywood colonies live inside the wood itself.
Subterranean colonies live in the soil and travel up into the structure.
Drywood termites
Drywood termites live entirely inside the wood they are eating. They need no
contact with soil and no external moisture source, which is why they can occupy a
roof rafter or a window frame indefinitely with nothing visible from below.
What you will see:
- Frass. These are the fecal pellets the colony pushes out through small
openings in the wood. They collect in small piles — on a windowsill, on the
floor beneath a beam, on top of a stored box in the garage. Six-sided, hard,
roughly the size of coarse sand, and usually the color of the wood. - Kick-out holes. Small, round openings, often plugged, where the frass
exits. - Blistered or hollow-sounding wood where galleries run beneath an intact
surface.
Frass is the giveaway. If you keep sweeping up a small pile of pellets in the
same spot and cannot work out where it is coming from, look directly above it.
Subterranean termites
Subterranean termites nest in soil. They need moisture and they need a protected
route into the structure, because they dry out in open air.
What you will see:
- Mud tubes. Pencil-width shelter tubes of soil and saliva running up
foundation walls, piers, or the inside of a crawl space. These are the highway
between the colony and the wood. - Damage that follows the grain and is packed with soil rather than clean.
- Wood that is intact on the surface but crumbles under pressure.
They almost never leave frass. What they leave is infrastructure.
Both species: swarmers
At certain times of year a mature colony produces winged reproductives that leave
to start new colonies. People find them at windowsills, or find discarded wings
in a neat pile after the fact.
Swarmers indicate a mature colony somewhere nearby — not necessarily inside your
house. The wings and bodies can help identify the species, so if you find them,
collect a few in a bag rather than vacuuming everything up. It is genuinely
useful to an inspector.
Timing varies by species, weather and year, so a swarm date is not by itself a
reliable identification.
Why this changes everything
The identification determines the treatment path, and the paths do not overlap:
Drywood — the colony is in the structure. Options run from
whole-structure fumigation to localized treatment,
depending on how many infestation points exist and how accessible they are.
Subterranean — the colony is in the ground, often outside the footprint of
the house entirely. Treatment focuses on the soil, with barriers and treated
zones. Fumigating the structure does nothing to a colony that does not live in
it.
This is why a diagnosis over the phone is not possible, and why any quote given
before an inspection is a guess about which of two unrelated jobs you need.
What to do before the inspection
Three things make an inspection more productive:
- Do not clean up the evidence. Leave the frass pile, leave the mud tube,
leave the wings. They tell an inspector more than a description does. - Note where you found it. A photo with a landmark in frame is ideal.
- Clear access. Move stored boxes away from the garage perimeter and clear
the crawl space hatch. Areas that cannot be reached get recorded as
inaccessible, and inaccessible areas are where problems hide.
Both at once
It is entirely possible to have both. They occupy different parts of a structure
and do not compete with each other. A house can have drywood in the roof framing
and subterranean at the foundation, and finding one is not a reason to stop
looking for the other.
That is one of the arguments for a full inspection rather than a targeted look at
the spot where you saw something. The pellets on the windowsill are information.
They are not the whole picture.
J&M Termite Control has identified and treated both species across the Bay
Area since 1973, under California Branch 3 registration #5223.
Request an inspection or read about
the treatment methods we use.
