Early Warning Signs of Termites in Sydney Homes

Last updated: October 2026

Termites work hidden. Most of the damage they cause is invisible until something fails: eaten-out timbers, hollowed bearers, galleries running through the framing. A sagging floor. A door that doesn't close right. A section of wall that sounds wrong. By the time those signs show, the damage behind them is already done.

What you can catch are the earlier signals: the signs termites leave when they're foraging, when a colony is sending out reproductives, or when conditions inside a wall shift in ways that show up on the surface. None of these proves anything on its own. Any of them in combination, especially after a wet period, is worth taking seriously.

How do you know if you have termites?

These are the signs I look for first, in the order I'd check them:

1. Mud tubes on brick piers, foundation walls, slab edges or inside the subfloor.
2. Hollow-sounding timber in skirting boards, door frames and architraves.
3. Brown, solid mud-like material pushed out of timber (not fine black dust).
4. Winged insects or shed wings near windows or lights, in spring and summer.
5. Doors and windows that stick, floors that sag, or paint that blisters over a flat surface.

One sign is a reason to look further. Two or more is a reason to book. The sections below cover each one.

Mud tubes on walls, piers, or slab edges

Mud shelter tubes are a direct sign of subterranean termite activity, and they're the one I look for first. Termites are soft-bodied and dry out quickly in open air. To cross a surface above ground, they build an enclosed tube from soil, saliva and other material. The tubes are usually about the width of a pencil, brown to dark grey, with a rough texture.

Where to find them:

• Subfloor brick piers. Look at the vertical face of the piers. A raised earthen construction running from the soil up the side of a pier, not a mark on the brick, is one of the more reliable signs of active ingress.
• Foundation walls. Along the outside base of the house, where soil sits close to brickwork or timber.
• Slab edges. Where the edge of the slab is visible at ground level, look for tubes running up and over the concrete face. This is why the 75 mm inspection zone matters: if you can see the slab edge, you can see a tube before it reaches the framing.
• Internal walls near wet areas. Less common, but tubes can appear on plaster near bathroom or laundry cavities if a colony has found a way up from the subfloor.

Old, dried, hollow tubes show past activity that may or may not have been treated. Fresh, solid tubes show activity now. I can tell which in a few minutes. If you've found one, don't knock it off. There's more in what to do about termite mud tubes.

Termite droppings and frass

Fine dust on the floor near skirting boards, on windowsills or under cornices is a common panic moment. Most of the time it isn't termites.

Ant frass is fine, black and dusty, like ground pepper. It falls in small loose piles near the ants' entry point.

Termite frass and workings are brown mud, solid in texture. Not powder, not dust. You might find it pushed out of small openings in timber or packed into crevices. It doesn't crumble into fine powder when you touch it.

Borer frass is the third one. It's a very fine pale or buff powder falling from small round exit holes in the timber. If you can see the holes, think borers before termites.

Fine, black and dusty is almost certainly ants. Brown, muddy and solid is a reason to call. If you've seen small hard pellets, a different group of termites (drywood) may be involved, and I'd want to see them. The full comparison is in termite frass vs ant frass.

Hollow-sounding timber

Subterranean termites eat timber from the inside out, leaving a thin shell of paint or veneer over a hollow core. The surface can look completely normal.

The test: run your knuckle firmly along skirting boards, door frames and any structural timber you can reach. Sound timber gives a dense, flat knock. Hollowed timber gives a papery, resonant sound, like tapping cardboard with air behind it. Once you've heard both, the difference is easy to pick.

Worth checking:

• Skirting boards near bathrooms, laundries and anywhere regularly damp. These are often the first affected when termites come in through wet conditions.
• Door frames and window architraves, particularly in older homes.
• Floor timbers near external walls. If a section feels soft or springy, it shouldn't.

A hollow sound alone isn't always termites. Old plaster can delaminate and timber can split. But hollow timber near a wet area, or near any other sign here, is worth a proper look.

Can you hear termites?

Sometimes, yes. In a quiet house, a faint rustling or clicking from inside a wall can be termites at work. Soldiers can also tap their heads against the timber when the colony is disturbed. It's a soft sound and most people never hear it, so silence tells you nothing.

If you do hear it, don't open the wall to look. Disturbing them can send them away from the spot, which makes the colony harder to find. Note where the sound is coming from and call me, because that tells me where to start.

Do termites eat gyprock?

Termites go for the paper facing on plasterboard, and they will tunnel behind and through it to reach the timber framing. The first sign is often not a hole at all. It's paint that bubbles or blisters over a flat wall, a faint hollow sound when you press the surface, or fine mud lines at the edge of a cornice or skirting board. There's more in termite damage signs in walls.

Doors and floors that have shifted

Termite damage to walls, door frames and floor systems can show up as movement when you open a door or walk across a floor.

• Sticking doors or windows. When the timber around an opening is damaged, the frame distorts. The door was fitted to a sound frame and the opening has changed shape. Worth noting in areas that have never had a moisture problem.
• Sagging floors. A soft spot, a bounce underfoot or a visible sag often means damage to the joists or bearers. This is a late sign. If the floor is sagging, the damage has been going for a while.
• Paint blistering over a flat surface. Where termites have eaten up behind a painted surface, the paint can lift in a bubble. That's different from normal paint failure, which cracks, flakes or chalks. If it's on a flat area and the spot sounds hollow when you press it, it needs checking.

Winged termites near windows in spring and summer

Mature subterranean termite colonies release winged reproductives, called alates or swarmers, to start new colonies. They fly on warm evenings, often after rain, and they go to light. In Sydney the swarms I get called to cluster around November, going on what turns up on jobs year after year. It is not a fixed date.

Swarmers don't mean your house has been infested. They do mean a mature colony is established somewhere near your property, and sometimes in the building. That's worth acting on.

To tell swarmers from flying ants: termites have two pairs of equal-length wings, straight antennae and a thick body with no pinched waist. Flying ants have a longer front pair of wings, elbowed antennae and a narrow waist. After landing, both shed their wings, and a small pile of wings on a windowsill is a sign a swarm came through. If you find wings inside the house, the source is close. Everything you need on the day is in flying termites in your house.

When to call

Any one of these signs on its own may have an innocent explanation. In combination, or in an older home with a history of moisture, the bar for calling is low. If you've found live termites and want to know which kind, my termite ID guide shows how to tell them apart by the soldier.

• Call now if you've found a mud tube, hollow timber near a wet area, or shed wings inside the house.
• Keep an eye on it and check the other signs if all you've noticed is a sticking door or blistering paint. Book if you can't rule termites out.
• Book an inspection at least once a year even if you haven't found any of these. Some things can't be seen from outside the walls, and that's the job of an inspection.

Book a termite inspection in Sydney, or a pre-purchase termite inspection if you're buying.

If you've spotted any of these, I'll come and have a look

If something here matches what you've found, the right next step is a proper inspection. I use a thermal imaging camera and a moisture meter on every job, and both pick up what a visual-only check misses. I write the report on-site and hand it to you before I leave. My report is written on the AS 4349.3-2010 timber pest inspection form.

If it turns out to be nothing structural, I'll tell you that directly. If there's something, you'll know what it is and what the options are. Inspections are from $330 (single storey) or $350 (two storey). Call me on 0405 790 927.

If termites are active, the options are a chemical barrier or a baiting system. Most chemical barrier and baiting systems on a Sydney home come in at around $5,000, depending on the size of the house and access. You get a written, itemised quote before anything starts. There's more on the treatment page.

Related reading: what an annual termite inspection checks.

Common questions

I found one of these signs but I'm not sure it's termites. Should I still call?
Yes, it's worth a look. Most of these signs have an innocent explanation on their own, but I'd rather check a false alarm than have you leave a real one. I'll tell you straight if it's nothing.

How do you know if you have termites?
Look for mud tubes, hollow-sounding timber, brown mud-like material pushed out of timber, winged insects or shed wings near windows, and doors or floors that have shifted. One sign is a reason to look further. Two or more is a reason to book an inspection.

Can you hear termites?
Sometimes. A faint rustling or clicking inside a wall in a quiet house can be termites. Most people never hear it, so not hearing anything doesn't mean you're clear.

Do termites eat gyprock?
They eat the paper facing and tunnel behind and through plasterboard to reach the timber framing. Blistered paint on a flat wall is often the first sign.

How quickly do termites cause real damage once these signs appear?
It depends on the size of the colony and how long it's been active, so I can't give a timeline without seeing the property. Visible signs like a sagging floor or a shed wing usually mean the activity behind the wall has been going for a while.

Can I check for these signs myself instead of booking an inspection?
You can and should keep watching, but a look from the surface misses what's happening inside the wall or under the floor. I use a thermal imaging camera and a moisture meter on every inspection because they pick up what your eyes can't.

Do these signs mean the whole house is affected?
Not necessarily. Activity is often in one area first, particularly near a moisture source. A proper inspection tells you the extent.