Carpenter Ants - Do they damage my house?

You spot a big black ant marching across your kitchen bench, and suddenly your mind jumps to worst-case scenarios. Are they eating my house? Is my timber doomed? Should I panic?

Take a breath. Carpenter ants have a reputation they don’t entirely deserve. They’re not chewing through your home like termites, but they are very good at moving in where conditions quietly suit them. Let’s clear up what carpenter ants actually do, and what they’re really telling you about your house.

Carpenter ants hollow out the timber structures

They do not consume timber the way termites do. Instead, they excavate wood to create tunnels and nesting galleries. The ants remove softened or damp timber and push out wood shavings (called frass) as they expand their nest. In other words, they don't eat the house; they hollow it out! Over time, this excavation weakens timber structures.

Damage to your house from carpenter ants usually happens slowly and quietly, which is why many homeowners are surprised when ants suddenly appear indoors.

Common areas affected include:

• wall studs and internal framing

• window and door frames

• decks, pergolas and verandas

• roof timbers and eaves

• bathrooms, laundries and kitchens

Carpenter Ants are structural engineers: They hollow out timber and design smooth, clean, interconnected galleries within the timber that follow the grain of the wood, which can maintain airflow and humidity and allow efficient movement of workers, brood, and queens.

Why carpenter ants choose certain houses:

Carpenter ants are extremely selective. They're not looking for "dirty" homes; they're looking for the right conditions:

• moisture (this is a big one)

• softened or water-damaged timber

• leaking pipes or roofs

• condensation on walls or ceilings

• poor drainage neur foundations

For many homes, carpenter ants are a warning sign of an underlying moisture issue.

Why do you often see them at night

Carpenter ants are mostly nocturnal. Seeing them

• at night

• along walls or ceilings

• in kitchens or bathrooms

Often means:

• then nest is nearby (sometimes inside the walls)

• workers are foraging for food and water

• The colony is established enough to send ants indoors

Seeing one ant doesn't always mean a serious infestation, but repeated sightings are a red flag.

Will Sprays Fix the Problem?

Surface sprays may

• kill visible ants,

• reduce activity briefly,

But they do not eliminate the nest.

In fact, spraying can:

• cause the colony to split

• push ants deeper into wall cavities

• make the problem harder to locate and treat.

Without addressing nest location and moisture sources, carpenter ants often return.

The Real takeaway about carpenter ants and structural damage

Carpenter ants aren't eating your house, but they may be telling you something important about it. They stay where moisture is present, timber is suitable and where conditions quietly support them.

Effective control isn't about blame or cleanliness. It is about finding the nest, fixing the conditions and treating the problem properly.

If you suspect carpenter ants, a professional inspection can determine whether damage is present, ants are nesting and what environmental factors are keeping them there.

Structural damage caused by carpenter ants is often underestimated, because it's slow, hidden and doesn't look dramatic at first. But over time, it can have real structural, financial and safety impacts, especially if moisture issues aren't addressed.