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The short answer
Termite mud tubes are pencil-width tunnels of soil that subterranean termites build to travel from the ground to timber without drying out. Finding one means termites are likely active nearby. Don't break it or spray it. Photograph it, leave it alone and book a termite inspection.
What are termite mud tubes made of?
Subterranean termites need moisture and can't cross open, dry ground or brick in the sun. So they build covered tunnels out of soil, mixed with saliva and other material, that keep the air damp and hide them from predators. The tunnels are often called leads or galleries. Most are about pencil width, though busy ones are wider.
The tubes look like dried mud, and they're brittle. They usually run in straight lines or hug a corner, and they connect the soil to a food source, which is your timber.
What types of mud tube are there?
Technicians name tubes by what they do. Knowing the type helps describe what you've found when you call.
| Tube type | What it looks like | What it tells us |
|---|---|---|
| Working tube | Wider, often runs up a pier, stump or wall | Steady traffic between the soil and the timber |
| Exploratory tube | Thinner, sometimes reaches out into the air | Termites searching for a way in |
| Drop tube | Hangs down from timber above to the ground | Termites already feeding above, linking back to the soil |
| Free-standing tube | Rises from the ground without a wall to lean on | Termites reaching for timber overhead |
A dry, crumbly tube with nothing moving inside might be old. Only an inspection can say if it's abandoned or if the termites simply moved to another route.
Where do mud tubes show up in Brisbane homes?
In a Queenslander on stumps, check the stumps, piers, bearers and the underside of the floor. Look at every pier top where timber meets concrete. In a slab-on-ground brick home, check the slab edge, weep holes, expansion joints, and the spot where a pipe or conduit comes through the slab.
Outside, look at fence posts, retaining walls, garden edging, pergola posts and meter boxes. Tubes on the back of a pergola post can lead straight to the house.
Should you destroy termite mud tubes?
No. Breaking a tube feels like the sensible thing to do, but it usually backfires. Termites rebuild, often in a new spot, and the colony may reroute through a gap you haven't found. The technician also needs the tube, and any live termites in it, to identify the species and trace the route back to the colony.
Spraying is worse. Household sprays can scatter termites deeper into the structure. Leave the tube alone, take clear photos with something for scale, like a coin, and book an inspection.
What is the difference between termite tubes and mud dauber nests?
Mud dauber and potter wasps also build with mud, so the two get confused. A few checks tell them apart:
- Termite tubes are flat tunnels that follow a surface, run up and down, and are thin and crumbly.
- Mud dauber nests are lumpy blobs or rows of tubes like organ pipes, often stuck under eaves, in corners or on walls.
- Wasp nests have round holes where the adult wasps come and go. Termite tubes have no such holes.
- Termite tubes connect to the ground or to timber. Wasp nests sit on their own.
- If you crack a termite tube open you'd find pale, soft insects. Wasp nests hold larvae or spiders, but please don't open either.
If the nest is a wasp nest, our wasp control page covers it. If you're unsure, a photo is enough to start.
How long does it take termites to build a mud tube?
There's no reliable fixed time. It depends on the size of the colony, the moisture, the temperature and how far the tube has to go. A big, active colony can extend a tube quickly in a warm, wet Brisbane summer.
What matters more is what a tube means. Someone has already done the work. Workers were in the timber, or on their way there, before you saw the tube.
What happens after you find one?
The next steps are simple, and the order matters.
- Leave the tube in place and take photos from a few angles.
- Note where it is, and whether it is dry or damp.
- Keep pets and kids away from the area.
- Book a termite inspection to AS 3660. Bruin's technician uses moisture meters and movement detection, checks the interior, subfloor and grounds, and gives you a written report.
- Get a quote for treatment once the extent is known. Bruin installs Trelona ATBS baiting and Termidor treated zones, with ongoing monitoring, and quotes after the inspection.
Our knowledgebase article on the signs of termites covers the other clues, like hollow timber and bubbling paint, that go along with tubes.
Sources and further reading
- CSIRO: termite research and biology
- Standards Australia: AS 3660 termite management
- QBCC: termite information for Queensland homeowners
General information for South East Queensland conditions. Every property is different; a licensed inspection is the only way to know what is going on in yours.