Termite damage is frequently invisible until it is structurally significant. Both subterranean and drywood species work concealed inside timber elements, leaving the external surface largely intact until the interior is severely compromised. These are the indicators that tell you activity is present — before visible structural failure occurs.
Mud tubes on walls, foundations, or timber
Active subterranean termite highwaySubterranean termite builds mud tubes to travel between the soil colony and the above-ground food source. Tubes are constructed from soil, chewed wood particles, and saliva — typically 10–15mm in diameter — and run along the face of foundations, slab edges, brick walls, and timber structures. A tube attached to the wall surface and running toward a timber element is the clearest indicator of active subterranean termite activity. Exploratory tubes (thin, irregular, suspended from a surface) indicate the colony is searching for new food sources. Mud tubes are unique to termites — there is no other pest that produces this structure.
Where to look
Hollow-sounding or papery timber
Internal structural destruction underwayTermites consume wood from the inside out, eating along the grain and leaving a thin external shell intact. Tapping or pressing on affected timber produces a hollow sound or a papery crumple rather than the solid resonance of sound wood. Window frames, door frames, skirting boards, architraves, floor joists, and structural beams can all be extensively compromised while appearing externally normal. In advanced cases, pressing a screwdriver tip gently into the timber surface penetrates with almost no resistance — the interior is gone. This sign requires immediate investigation of surrounding structure, as the damage typically extends significantly beyond the initial discovery point.
Where to look
Frass (drywood termite pellet mounds)
Active drywood termite colonyDrywood termite ejects its waste (frass) from the gallery through small "kickout holes" in the timber surface. Drywood termite frass is distinctive: hexagonal ovoid pellets, approximately 1mm long, uniform in size and shape, forming a small mound or scatter beneath the infested timber. The pellets are the colour of the timber being consumed (pale for soft wood, darker for hardwoods). Frass mounds typically appear on surfaces below the infested timber — on windowsills, beneath furniture, on floors below roof trusses. The kickout hole above the mound is often visible as a tiny pinhole in the timber surface. Drywood termite does not require soil contact and is commonly found in roof trusses, furniture, and door frames.
Where to look
Discarded wings (swarmer alates)
Colony expansion phase — new colony riskTermite swarmers (alates) are winged reproductive termites released from a mature colony during the expansion phase — typically during warm, humid weather after the first summer rains. After a brief flight, alates shed their wings and attempt to found new colonies. Finding a pile of small discarded wings — typically around window frames, door frames, or light sources — indicates a swarm event has occurred nearby. This does not necessarily mean the swarm originated from within your structure (it may have flown in from a neighbouring property), but it confirms a mature termite colony is active in the area. Any existing timber elements should be inspected following a swarm event.
Where to look
Blistered or bubbled paint over timber
Moisture or active termite behind surfacePaint blistering or bubbling over a timber surface can indicate two causes: moisture trapped behind the paint from a water leak, or an active termite gallery close to the surface. Subterranean termite working near the surface of a timber element can introduce sufficient moisture from the colony transport system to blister the paint above it. The distinction matters: if blistering is accompanied by other termite indicators (mud tubes nearby, hollow sound when tapped), the blister requires opening to inspect the underlying timber. If the paint surface above the blister is pushed inward slightly rather than outward, this suggests a cavity behind it — which may be a termite gallery.
Where to look
Visible structural damage or collapse of timber
Advanced — load-bearing riskIn advanced infestations, the external timber shell becomes too thin to maintain structural integrity and the surface crumbles, collapses, or deforms under normal load. A floor section that feels spongy underfoot, a door frame that has visibly distorted, a skirting board that crumbles when touched, or a roof truss that shows visible deformation are all indicators of extensive structural compromise. This stage represents a significant structural engineering concern — not just a pest management issue. Structural assessment by an engineer or qualified builder may be required in addition to the termite programme. At this stage, the immediate priority is to identify the full extent of structural compromise before any remediation work begins.
Where to look
The signs present and their location determine whether the programme is inspection and monitoring, active treatment, or a combined structural and pest remediation.
| Level | Indicators |
|---|---|
| Cosmetic | Discarded wings only; frass under one timber element; no mud tubes; no hollow timber found |
| Active | Mud tubes confirmed on foundation or wall; hollow timber at 1–2 locations; frass at multiple points |
| Established | Multiple mud tubes; hollow timber at 3+ locations; paint blistering; structural elements affected |
| Structural | Visible timber collapse or deformation; load-bearing elements compromised; extensive gallery system |
Subterranean termite originates from a soil colony and requires a moisture connection — all activity can be traced back to a ground entry point. The diagnostic inspection focuses on the slab perimeter, all pipe penetrations, and the subfloor or crawl space. Drywood termite requires no soil contact and is found in dry timber — roof trusses, furniture, door and window frames — anywhere in the structure. These are treated differently: subterranean termite requires a soil chemical barrier or bait system; drywood termite requires localised fumigation or heat treatment of the affected elements — see soil barrier, bait system, and fumigation programmes — which species requires which approach.
A single property can have both species active simultaneously. The inspection determines which species is present at each location and the programme is designed accordingly.
Inspection
Termite inspection Cape Town
Full structural timber inspection: what we check, the report format, and guarantee terms.
Differential diagnosis
Termites or wood borer?
Mud tubes and hollow timber vs round exit holes and powdery frass — the signs that separate the two before treatment is committed.
Methodology
Termite treatment
Soil chemical barrier, bait systems, and drywood fumigation — which approach applies when.
A professional inspection determines whether activity is current, identifies the species, maps the full extent of damage, and produces a written treatment and remediation plan. Do not delay — termite damage compounds significantly over weeks.
Book inspection