How to Get Rid of Carpenter Ants: Complete Homeowner Guide

Carpenter ants (Camponotus spp.) are one of the most common structural pests in homes, especially in areas with wooden buildings and high moisture. They do not eat wood like termites, they do not metabolise it, but they excavate galleries and tunnels inside the wood to build their nests. This makes them a hidden but serious threat for our properties.

Many homeowners first notice them in the kitchen,in the basement, around windows or around the house, or crawling on walls. Others discover piles of  “sawdust” known as frass. If untreated, a colony can grow and spread through walls, floors, and roofs to all your wooden furniture. It takes years, but is is a possibility, so here comes the question: how to get rid of carpenter ants?

For a full explanation of their biology, nesting behaviour, and global distribution, see our detailed guide: Carpenter Ants (Camponotus spp.) – Identification & Damage.

Identification

Carpenter ants are often confused with other large ants, but a few details can help you identify them correctly:

• Size: 6–13 mm depending on caste

• Color: Black or black-and-red depending on species

• Shape: Smooth, rounded thorax when viewed from the side

• Waist: Narrow, one node

• Antennae: Elbowed, 12 segments

• Wings: Swarmers have long clear wings (spring–summer)

• Frass: Wood shavings mixed with insect parts outside nest openings

Carpenter ants forage mostly at night, forming trails along foundations, trees, and utility lines.

To avoid confusion, compare them with:

• Termites, which have straight antennae, no neck,  and soft yellowwhite bodies

• Pavement ants, which have uneven thorax and are much smaller

• Odorous house ants, which produce a rotten smell when crushed

Biology & Ecology

Carpenter ants nest in two types of structures:

Primary nest

Contains the queen and brood. Usually located outdoors in:

• Old tree stumps

• Logs

• Firewood

• Moist, decayed wood

Satellite nests

Built indoors once the colony grows:

• Wall voids

• Door frames

• Roof beams

• Attics

• Behind dishwashers or sinks

• The furniture

They prefer moist or water-damaged wood because it is easier to excavate. This is why leaks, humidity, and poor ventilation are major risk factors.

Diet

Carpenter ants do not eat wood.
They feed on:

• Honeydew from aphids and scale insects

• Household sweets and proteins

• Pet food

• Dead insects

• Fruit juices

Global Distribution

Carpenter ants exist almost everywhere:

• North America: C. pennsylvanicus, C. modoc, C. floridanus

• Europe: C. herculeanus, C. ligniperda

• Asia: Diverse forest species

• Australia: Native Camponotus species in urban and rural areas

They thrive in temperate and humid climates, where moisture and wooden structures are abundant.

Risks / Damage

Carpenter ants cause structural damage by hollowing wood. They may attack:

• Roof beams

• Support columns

• Window frames

• Wall studs

• Decks

• Trees around the property

They prefer moist wood but can extend into dry, solid wood as colonies grow.

Signs of Infestation

Look for:

• Frass: Sawdust-like piles under walls or ceilings

• Clicking or rustling sounds inside walls

• Moisture issues near nesting areas

• Trailing ants indoors at night

• Winged swarmers indoors around the windows during spring

• Splitting or hollow-sounding wood 

How to Get Rid of Carpenter Ants

Removing carpenter ants requires eliminating both the colony and the conditions that support it.

Step 1: Fix Moisture

Very important. Moisture is the main reason carpenter ants invade the woods.

• Repair leaking roofs, pipes, and windows

• Improve ventilation in attics and basements

• Reduce humidity with dehumidifiers

• Replace rotted wood as fast as possible.

Step 2: Find the Nest

The nest may be indoors or outdoors and it is difficult to find it.

Common indoor locations:

• Wall voids near bathrooms

• Inside door frames

• Under window sills

• Attics

Common outdoor locations:

• Tree stumps

• Deck posts

• Firewood piles

• Old fences

Step 3: Use Baits

Carpenter ant baits work slowly and most times effectively, it is produced in a way that is allowed from workers to pass the toxic food back to the colony and spread to everyone. If the queen eat it the colony collapses.

Effective bait types:

• Protein baits (early season)

• Sugar baits (later season)

Use only legal in your country, ready-to-use retail products. Or call an expert.

Step 4: Treat the Nest (If Located)

For nests inside walls, professionals often use:

• Residual insecticides around entry points or injected by an expert to the galleries. That is very difficult, in fact you have to inject a lot of spots on the wood that you believe they pass through, but is not sure.

• Non-repellent sprays along trails

Do not drill walls or inject chemicals yourself unless you are licensed or allowed by local law.

Step 5: Kill Satellite Nests

Carpenter ants often have multiple satellite nests. That makes the treatment even more difficult. Eliminating only one nest will not solve the problem.

IPM approach:

• Identify all moisture sources

• Inspect all wooden structures

• Combine baiting with dusts

• Follow-up inspection after 2–4 weeks

Advanced / Professional Approaches

Pest control companies use:

• Infrared thermal imaging to spot nest heat, this is helpful.

• Moisture meters to locate humidity pockets

• Insect Growth Regulators (IGRs) to disrupt colony development

• Foam treatments for deep voids

• Perimeter non-repellent treatment to intercept foragers

Professional treatment is essential for large, long-established infestations.

FAQ Section

Q1. What is the fastest way to get rid of carpenter ants?
Using both moisture control and baiting together.

Q2. Do carpenter ants bite?
Yes, but rarely. Bites cause only mild irritation.

Q3. Can carpenter ants damage a home?
Yes, long-term infestations can weaken wood structures. Don't worry, it takes a long time.

Q4. Why do carpenter ants appear in my kitchen?
They are searching for sweets, proteins, and moisture.

Q5. Are carpenter ants worse than termites?
They destroy wood more slowly, but still cause major damage.

Q6. Should I spray ants directly?
No. Spraying kills only workers that are outside the nest

Q7. Do carpenter ants have a queen?
Yes. Only the primary nest has the queen.

Q8. Can I get rid of carpenter ants without chemicals?
You can reduce moisture and remove food sources, but full elimination is difficult without baiting or dusts.

Final Thoughts

Carpenter ants (Camponotus spp.) are one of the most common structural pests found in homes. They do not eat wood, but their nesting activity weakens it over time, creating galleries inside beams, roofs, window frames, and walls. Because they often build satellite nests far from the original colony, infestations can spread silently for years.

The most effective strategy is always a combination of moisture control, proper inspection, and targeted baiting. Removing water leaks, sealing entry points, improving ventilation, and trimming vegetation around the house can drastically reduce the risk of infestation. But it took time for the infestation to become severe, needs time to get rid of them. When nests are inside walls or ceilings, or when multiple satellite nests exist, professional help becomes necessary.

Early detection saves money. Any homeowner who notices frass, nighttime activity, or winged swarmers indoors should act immediately. With a proper integrated pest management (IPM) approach, carpenter ant problems can be eliminated safely and effectively.

Disclaimer

This article is for informational purposes only. Pest control laws and approved chemicals vary by country. For best results and legal safety, we strongly recommend contacting a licensed pest control professional in your local area. Always make sure that the pest control technician is properly certified or licensed, depending on your country’s regulations. It’s important to confirm that they only use approved products and apply them exactly as instructed on the product label. In most places in Europe, the UK, or the USA, following label directions is not just best practice—it’s the law.

Author

Nasos Iliopoulos, BSc Agronomist & Certified Pest Control Expert
Scientific Director – Advance Services (Athens, Greece)
Licensed Pest Control Business – Ministry of Rural Development & Food (GR)

References

1. University of Minnesota Extension – Carpenter Ants

2. Penn State Extension – Carpenter Ant Management

3. UC IPM – Carpenter Ants