Termite Frass: The Pile of Dust That Should Worry You
There's a small mound of what looks like coarsely ground coffee sitting on your floorboards. You sweep it up, think nothing more about it, and three days later it's back in exactly the same spot. That, in all likelihood, is termite frass, and the reason it keeps returning is that something above it is still eating.
What termite frass actually is
Frass is termite excrement. Drywood termites live entirely inside the timber they consume, with no soil contact and no need for the mud galleries that subterranean species build. They have no way to dispose of waste except to push it out.
So they chew small openings in the surface of the timber, called kick holes, and eject their droppings through them. The pellets accumulate below in neat, conical piles. It's tidy, methodical housekeeping, and it's the only external evidence a drywood colony ever produces.
What it looks like and where it appears
Termite droppings are six sided pellets, roughly one millimetre long, uniform in size and hard. To the naked eye they look like coarse coffee grounds, fine sawdust or very small grains of sand. Under a magnifying glass the six flattened faces become obvious, and that's the identification that settles the question.
Look for it beneath skirting boards, window and door frames, timber furniture, roof timbers, and around the edges of hardwood flooring. It gathers on windowsills, along wall junctions and on top of anything horizontal sitting under infested timber.
Frass versus sawdust versus ant debris
Three different piles of small brown material, three completely different problems and three completely different responses.
| Debris type | Appearance | What it means |
|---|---|---|
| Termite frass | Uniform hard six sided pellets, roughly 1mm, gritty | Drywood termites inside the timber |
| Sawdust from borers | Fine powdery flour like dust, soft | Wood boring beetle activity |
| Carpenter ant debris | Coarse irregular shavings mixed with insect parts and soil | Ants excavating, not eating, the timber |
| General household dust | Soft, grey, non uniform, no pattern | Nothing |
The tests are simple. Rub it between your fingers. Frass is gritty and holds its shape. Borer dust crushes to powder. Carpenter ant debris feels like fine wood shavings and often contains bits of dead insect. Our guide to telling carpenter ants from termites covers that distinction in more depth.
Why only some species produce it
This is the useful diagnostic. Subterranean termites, which are the species doing most of the structural damage across Townsville, do not produce visible frass. They mix their waste into the mud they use to build shelter tubes and gallery linings. It's structural material rather than rubbish.
So if you're finding frass, you're most likely dealing with drywood termites, several Cryptotermes species of which occur in Queensland. That changes the treatment approach considerably, because there's no soil connection to intercept and no nest in the ground to target.
It also means the absence of frass proves nothing. Plenty of Townsville homes with serious Coptotermes or Mastotermes activity have never produced a single pellet.
What the colour tells you
Frass takes its colour from the timber the colony is eating, which is genuinely useful information. Pale cream or light tan frass suggests softwood, often pine framing or trim. Mid brown suggests a hardwood. Very dark, almost black frass usually means dense old hardwood, which in a Townsville Queenslander often means structural timber rather than trim.
Darker frass in an older home is therefore worth taking more seriously, not less. It suggests the colony has moved past the easy material. See what termite damage looks like in hardwood for what that progression actually looks like once opened up.
Why sweeping it up is the worst response
It's the instinctive thing to do and it destroys your only diagnostic tool. The pile tells a technician three things: where the kick hole is, what timber is being eaten, and how active the colony currently is. Volume over time is the single best proxy available for how fast an infestation is progressing.
If you want to know whether it's active, do this instead. Photograph the pile with something for scale, a coin works. Clear it away completely. Mark the date. Come back in a week. If there's a fresh pile, the colony is feeding right now, and you know roughly how quickly.
Finding the kick hole
Look directly above the pile. Kick holes are small, usually under two millimetres, round and clean edged, and they're often plugged when not in use, which makes them genuinely hard to spot. A torch held at a low angle across the timber surface throws shadows that reveal them.
Once you've found one, look for others. Drywood colonies typically maintain several. Mark them lightly with pencil rather than covering them, because a technician will want to inspect them and may want to introduce a treatment through them.
Getting it identified properly
Collect a sample. A teaspoon in a small jar or a zip bag is ample, and it survives transport perfectly well. Note where it came from, what's above it and how long it's been accumulating.
Then book an inspection. Frass confirms activity but it doesn't tell you the extent, and extent is what determines cost. It is worth also checking the nine signs of termites elsewhere in the house, since frass rarely appears alone. Drywood infestations can be localised enough to treat in a single timber member, or extensive enough to require whole of structure treatment. The only way to know which is to look.
JJM Pest Management has been carrying out termite treatment in Townsville for more than twenty years. Call 07 4774 3316 and bring the jar.
Frequently asked questions
What does termite frass look like?
Small hard six sided pellets around one millimetre long, uniform in size, resembling coarse coffee grounds or fine sand. Colour ranges from pale cream to near black depending on the timber being eaten. Under magnification the six flattened faces are clearly visible.
Does frass mean I definitely have termites?
It strongly indicates drywood termite activity, but it can be confused with wood borer dust or carpenter ant debris. Borer dust is fine and powdery rather than pelletised. Carpenter ant debris is coarse and irregular and often contains insect fragments. A sample and a professional identification settles it.
Why do I have frass but no visible termites?
Drywood termites live entirely inside the timber and rarely emerge. You will almost never see them without opening up the affected wood. The frass is the only external evidence they produce, which is exactly why it matters.
Can I just plug the hole and forget about it?
No. Sealing a kick hole does not affect the colony inside the timber, which continues feeding and will simply open another. It also removes your ability to monitor activity. Leave it and get it inspected.
Is drywood termite damage as serious as subterranean damage?
Drywood colonies are typically smaller and slower than subterranean ones, so damage generally accumulates over a longer period. That said, they can persist for years undetected in roof timbers and furniture, and the total damage can be substantial. It is a slower problem rather than a smaller one.
