Signs of Termites in a House: 7 Early Warnings and What to Do When You See Them

Why are termites so hard to spot?

Termites do not show themselves like cockroaches or ordinary ants. They live in the soil or inside timber and travel in enclosed tunnels, because they need moisture and avoid light and dry air. An infestation can therefore run for a long time before anyone notices, and it is often discovered by chance during maintenance or when part of a door frame collapses.

Knowing the signs of termites in a house means looking at the evidence they leave behind, not at the insect itself. By behaviour, termites fall into two main groups: subterranean termites, which come from the soil and need contact with it, and drywood termites, which live inside dry timber with no need for soil. Each leaves different signs, and sometimes the difference between them decides the whole treatment.

Which signs of termites in a house should you watch for?

1. Mud tubes

The UC Statewide IPM Program says mud shelter tubes are the most common evidence of subterranean termite infestation. They look like brown lines about as wide as a pencil, climbing foundations or walls, running behind cupboards, or hanging from the ceiling. If you break off a small piece and find small white insects, the infestation is active.

2. Swarms and shed wings

In certain seasons winged individuals leave the colony to found new ones. You may see them flying around lights or windows, or find their discarded wings in quantity near thresholds and window sills. A lot of wings inside the house usually means the colony is very close or inside the building.

3. Hollow-sounding timber

The US Environmental Protection Agency advises checking exposed wood by tapping it or pressing with a flat screwdriver to find hollow areas. Termites eat wood from the inside and leave a thin outer shell, so a door frame can look sound while a screwdriver sinks into it easily.

4. Bubbling paint and rippled surfaces

The UC programme notes that infested wood can darken or swell. On gypsum and paint you may see rippling or blisters that look like damp damage, because termites carry mud and moisture with them. Sometimes there are tiny pinhead-sized holes in the paint.

5. Frass pellets

Drywood termites push their droppings out through small holes. The UC programme describes these pellets as six-sided and a distinctive sign of this type, and says their kick-out holes are smaller than 2 mm. They look like small piles of sand or coloured sawdust under furniture, doors or timber ceilings.

6. Doors and windows that stick

Moisture that termites bring into timber frames can make them swell and jam. This sign is non-specific because damp has other causes, but it deserves inspection if it appears with another sign. Some residents also notice a faint tapping or rustling inside wood in quiet moments, or feel that timber floors have gone soft in particular spots.

7. Galleries that follow the grain

When a piece of infested timber is broken open, it shows hollow channels running with the grain, and in the subterranean type they are soiled with mud. This is what the technician sees when inspecting suspect elements.

How do you tell a winged termite from a flying ant?

In swarm season many people confuse the two. The US Environmental Protection Agency explains the following differences:

What should you do if you see signs of termites?

1. 1

   Do not break the tunnels or spray a pesticide

   Random spraying kills only the visible individuals and pushes the colony to change course, making it harder for the technician to trace later.

2. 2

   Document what you see

   Photograph the tunnels, wings, pellets and damaged wood, noting where they are, and keep a sample of wings or insects in a sealed bag for identification.

3. 3

   Check moisture sources

   Subterranean termites need moisture. Check for pipe leaks, air-conditioner condensate and standing water near the foundations.

4. 4

   Ask a licensed provider to inspect

   Identifying the type and the extent of infestation takes experience, and the choice of treatment depends on it. The UC programme stresses that most proven methods are for professional use.

5. 5

   Assess structural damage

   If termites have attacked load-bearing timber or ceilings, a technical assessment may be needed to replace them after treatment.

What treatment methods might the technician suggest?

For subterranean termites, professional options include treating the soil around and under the building with a chemical barrier, bait stations with a slow-acting active ingredient, or injecting the tunnels directly. For drywood termites, treatment may be localised to the infested item or cover the whole building, depending on the extent. The pesticide, its dose and the time you must stay away are set by the product label and the licensed provider, not the homeowner.

After treatment comes prevention: keeping timber out of contact with soil, repairing leaks, and draining water away from foundations. In homes with persistent ground moisture, it helps to review waterproofing for the foundations and lower walls.

Make sure the technician's report after inspection states the specific termite type, the infested locations, the proposed method, the registered product name and the follow-up visit date. This report helps you later when selling the house or if the infestation recurs.

To request an inspection for the signs you have noticed, see our pest control service. The check can also be part of a home inspection when buying a second-hand house, because hidden infestation is one of the defects that an ordinary viewing rarely reveals. Prevention during construction is covered in termite control before building.