Drywood termites: no soil, no moisture, no barrier to cross
Almost everything written about Australian termite management assumes the colony lives in the ground. This group does not, and that changes the whole answer.
A colony that never leaves the timber
The termites that shaped Australian building practice are subterranean: the colony lives in the soil or in a concealed central nest. And workers commute to your timber and back. That is why they build mud tubes, and why the entire apparatus of soil barriers, physical barriers under a slab and inspection zones exists. Interrupt the commute and you have done something useful.
Drywood termites (the genus you will hear named is Cryptotermes) do not commute. The whole colony lives inside the piece of timber it is eating. It takes the moisture it needs from the timber itself and from its own metabolism. So it does not need ground contact, it does not need a leak, and it does not need to come out. A drywood colony can live its entire life inside a single roof batten, a window frame, a piece of furniture or a stack of skirting boards.
That one difference invalidates most of the standard advice. A soil barrier protects a perimeter that this group never crosses. A bait station works by feeding a slow-acting active to foraging workers that carry it home, and these workers do not forage. Reducing moisture around the house, which genuinely matters for subterranean species, does very little here.
How the two groups actually differ
| Subterranean (Coptotermes, Schedorhinotermes, Nasutitermes) | Drywood (Cryptotermes) | |
|---|---|---|
| Where the colony lives | In soil, a tree, a stump or a concealed central nest away from the timber | Entirely inside the timber it is eating |
| Soil contact | Required. The link to the ground is the vulnerability | Not required at all |
| Moisture source | Needs a moist environment and humid galleries | Takes what it needs from the timber |
| What you find | Mud tubes, mud-packed galleries, no visible droppings | Hard six-sided pellets pushed out of small holes |
| Colony size | Tens of thousands to millions | Hundreds to a few thousand |
| What management targets | The soil link and the foraging population | The infested timber itself |
The pellets are the give-away
Subterranean termites recycle their faeces into building material (it is what mud tubes and gallery linings are made of) so you do not find droppings from them. Drywood termites do the opposite. They keep their galleries clean by pushing waste out through small kick-out holes, and it accumulates below as a small pile.
The pellets are distinctive: hard, dry, roughly the size of coarse sand. And six-sided with concave faces, which is why a pile of them can look faintly like a heap of tiny pepper grains. They fall straight down, so the pile sits directly beneath the hole. If you sweep it away and it comes back, the colony above is active. Reading a pile of debris goes through how these compare with borer frass and with ordinary dust and grit.
Do not sweep it away. The position of the pile is what tells an inspector where the kick-out hole is. And the hole is what tells them which board is infested. A swept floor is a floor with the evidence removed from it.
The species that makes this more than a curiosity
Australia has native Cryptotermes species, and in most of the country drywood damage is a slow, localised problem confined to the piece of timber involved. Small colonies eat slowly; damage accumulates over years, not months.
The exception is the West Indian drywood termite, Cryptotermes brevis, which is not native here. It is an introduced pest, it moves between buildings in infested timber and furniture rather than through the ground. And it is capable of doing serious damage to a house. Because it travels in objects, the usual controls are about detection and movement rather than soil.
This species is treated as a notifiable pest in parts of Australia, notably Queensland. A confirmed detection has to be reported to the state authority, and there are rules about moving infested material.
Whether that applies to you, and what exactly it requires, is a question for your state's building or primary industries authority. We set out the mechanism here and do not interpret the obligation for you. If you are in Queensland, the QBCC page linked in the sources is the right starting point.
Why identification still is not yours to make
Hexagonal pellets under a small hole are a strong pointer towards drywood termites, and it is reasonable to arrive at that suspicion yourself. It is not an identification. Powderpost beetles and other timber borers also push waste out of small holes, and their frass is a different thing. Finer, more like flour or fine sand, and often packed in the tunnel rather than kicked clear. The two problems have different answers.
Going further than the group (which Cryptotermes species, and in particular whether it is C. brevis) is done on soldiers under magnification by someone qualified, because the consequences of that particular call are not trivial. Nobody can make it from a photograph, and we will not attempt to. What genuinely helps is to collect a small sample of the pellets in a sealed container, note the date and the exact spot they fell, photograph the hole. And hand all of it to the inspector.
What is done about it — and who does it
Because the colony is in the timber and not in the ground, management is directed at the timber. The options professionals work with range from treating or replacing the affected members through to whole-of-structure approaches for a widespread infestation. Which one is appropriate depends on how far it has spread, which is exactly what an inspection to AS 4349.3 is for.
Every termiticide used in Australia is registered by the APVMA and applied by a licensed pest management technician. Nothing sold over a counter is a treatment for a drywood colony living inside a structural member. And the surface sprays that look like they might be will not reach it: the insects are not on the surface. Filling the kick-out holes achieves less than nothing: it hides the only evidence you have while the colony carries on.
What to do
Leave it exactly as it is. Do not sweep the pellets, do not plug the holes, do not prise the board up to see how far the damage goes, and do not spray anything at it. The pile, the hole and the sound of the timber are the whole evidence set. And every one of those actions destroys part of it while leaving the colony where it is.
Photograph the pile in place with something for scale, keep a sample, and book an inspection. If you want to check the rest of the house first without touching anything, the fifteen-minute walk-around is the touch-nothing version. And how barriers work explains why the protection you may already have under the slab was never aimed at this group.
Frequently asked questions
Do I still need a termite barrier if I have drywood termites?
A soil barrier does nothing about a drywood colony, because that colony never crosses the soil. It is still worth having for the subterranean species, which are the ones that cause most Australian structural damage and which do come from the ground. The two problems are separate and a house can have either, both or neither.
How do I tell drywood termite pellets from borer frass?
Termite pellets are hard, dry and six-sided with concave faces, roughly the size of coarse sand, and they sit in a loose pile below a small hole. Borer frass is generally finer (closer to flour or fine sawdust) and is often packed inside the tunnel rather than kicked out. It is a useful distinction to notice, but it is a pointer for the inspector, not a diagnosis.
Can drywood termites spread through the house from one board?
They can spread, but not the way subterranean termites do. There is no foraging network moving through the structure. Spread happens when winged reproductives leave a mature colony and start a new one in another piece of exposed timber, or when infested timber or furniture is physically moved. That is why a detection is treated as a question about the whole building, not just the board you found.
Is it true that drywood termites have to be reported?
For one species it can be. Cryptotermes brevis, the West Indian drywood termite, is an introduced pest treated as notifiable in parts of Australia, Queensland in particular, with rules about reporting a confirmed detection and moving infested material. Whether that applies in your case is a matter for your state authority: ask them or the inspector who made the identification.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- Queensland Building and Construction Commission. Protect against termites — termite management systems and inspections
- Department of Health, Victoria. Pest control — termites
- Australian Pesticides and Veterinary Medicines Authority. Registered agvet chemical products (PubCRIS)