Finding large black ants inside your home can be concerning, especially when those ants may be carpenter ants.
Carpenter ants are one of the more common wood-infesting ants found in Ontario. Unlike termites, carpenter ants do not eat wood. Instead, they excavate tunnels and galleries inside wood to create space for their nests. Over time, an established colony can contribute to significant wood damage. Canada
At GBG Pest Control, we help homeowners and businesses identify carpenter ant activity, locate potential nesting areas, and develop effective pest-management solutions.
What Are Carpenter Ants?
Carpenter ants belong to the Camponotus genus and can vary considerably in size and colour.
In Canada, carpenter ants can range from approximately 6 to 25 mm in length. Black and reddish carpenter ants are among the types commonly encountered. Canada
Some characteristics that can help distinguish carpenter ants from other insects include:
- A narrow or constricted waist
- Bent or “elbowed” antennae
- A smoothly rounded thorax
- Larger workers compared with many other household ants
- Wings on reproductive ants during swarming periods
Because different ant species can look similar, identification is important before deciding on a treatment strategy.
Do Carpenter Ants Eat Wood?
No. Carpenter ants do not eat wood.
This is one of the most common misconceptions about them.
Instead, carpenter ants excavate wood to create nesting galleries. The material they remove is pushed out of the nest and may appear as sawdust-like debris or frass.
Health Canada notes that carpenter ants can tunnel through wood while using the excavated material to create their nests. Canada
The important issue for homeowners is that repeated excavation can weaken susceptible wood, particularly when a colony remains established for an extended period.
Why Are Carpenter Ants in My Home?
Carpenter ants are often associated with moisture and deteriorating wood.
Potential nesting locations include:
- Damp or damaged wood
- Wall voids
- Attics
- Around windows and doors
- Areas around plumbing
- Roof structures
- Hollow doors
- Crawl spaces
- Decks and other wooden structures
- Tree stumps and decaying trees near the property
Moisture problems can make wood more attractive to carpenter ants.
A leaking roof, plumbing issue, poor ventilation, condensation, or water damage can therefore create conditions that make a property more vulnerable.
Signs of a Carpenter Ant Infestation
Seeing one large ant does not necessarily mean you have an established colony inside your house.
However, repeated activity should not be ignored.
Look for signs such as:
1. Large Ants Inside the Home
Repeated sightings of large ants, especially in the same area, may indicate a nearby nest or established foraging route.
2. Sawdust-Like Material
Small piles of coarse material near cracks, walls, window frames, ceilings, or wooden structures can be an indication that ants are excavating wood.
This material is commonly referred to as frass.
3. Winged Ants
Winged carpenter ants may appear during reproductive periods. Finding numerous winged ants inside a building can indicate that a colony may be established within the structure. Muskoka Pest Control+1
4. Ant Trails
Carpenter ants may travel along predictable routes while searching for food.
Pay attention to activity around:
- Windows
- Doors
- Pipes
- Utility lines
- Wall openings
- Roof edges
- Tree branches touching the building
5. Rustling Sounds
In some situations, an active colony inside a wall or other enclosed area can produce a faint rustling or movement sound.
This may be more noticeable at night when the house is quiet.
Carpenter Ants vs. Termites
Carpenter ants are sometimes confused with termites, but they are very different insects.
| Carpenter Ants | Termites |
|---|---|
| Narrow waist | Broad waist |
| Bent antennae | Straight antennae |
| Darker body commonly seen | Often lighter-coloured |
| Wood is excavated, not eaten | Wood is consumed |
| Front wings are longer than hind wings | Wings are generally similar in length |
Correct identification matters because the control strategy for carpenter ants is different from the approach used for termites. Canada
If you are unsure what type of insect you are seeing, professional identification can prevent you from spending money on the wrong treatment.
Are Carpenter Ants Dangerous?
Carpenter ants generally aren’t considered dangerous to people in the way some stinging or biting pests can be.
The bigger concern is property damage.
Carpenter ants excavate wood to create nesting galleries. If a colony remains active for a long period, the damage can become more significant, particularly where wood is already weakened by moisture or decay. Canada
That is why repeated carpenter-ant activity deserves attention.
Carpenter Ants in the Spring
Carpenter ant activity can become particularly noticeable during the spring.
Homeowners may suddenly notice ants appearing indoors after months of seeing little or no activity.
Spring sightings can occur because colonies become more active as temperatures increase. Winged reproductive ants may also appear during seasonal swarming periods. Muskoka Pest Control+1
However, seeing carpenter ants in your house does not automatically prove that the main colony is inside.
The ants may be coming from an outdoor colony and entering the structure while searching for food or shelter.
A professional inspection can help determine the likely source.
Carpenter Ants During Winter
Finding carpenter ants indoors during colder months can be especially worth investigating.
If carpenter ants are active inside during winter, there may be a colony or suitable nesting area within the building, although individual ants can also enter homes through other means.
This is one reason that when you see the ants can be useful information when diagnosing a pest problem.
Keep track of:
- When you first noticed them
- Where you see them
- How frequently they appear
- Whether you see them during the day or night
- Whether you see winged ants
- Whether there is frass nearby
These details can help a pest-control professional narrow down the potential source.
How to Prevent Carpenter Ants
Prevention begins with making your property less attractive to carpenter ants.
Control Moisture
Repair leaks and address moisture problems around:
- Roofs
- Plumbing
- Basements
- Bathrooms
- Attics
- Windows
- Exterior walls
Moisture-damaged wood should be repaired or replaced where necessary.
Keep Firewood Away From the House
Avoid storing large quantities of firewood directly against your home’s exterior.
Firewood can provide shelter for ants and other pests, and moving it directly beside the house can make pest entry easier.
Trim Vegetation
Tree branches and vegetation touching or overhanging the building can provide routes for ants to reach the structure.
Keep branches appropriately trimmed and inspect trees near the home for signs of decay.
Remove Decaying Wood
Stumps, rotting logs, old boards, and other deteriorating wood around a property can provide potential nesting locations.
Removing these materials can reduce available habitat around your home.
Seal Potential Entry Points
Inspect around:
- Windows
- Doors
- Foundation cracks
- Utility penetrations
- Pipes
- Vents
- Exterior openings
Sealing appropriate entry points can make it more difficult for ants to enter.
Can You Get Rid of Carpenter Ants Yourself?
Some homeowners try over-the-counter sprays when they see carpenter ants.
The problem is that killing the ants you see does not necessarily eliminate the colony.
For example, worker ants may simply be foraging between an outdoor colony and the building.
A surface treatment may reduce visible activity without addressing the nest.
For long-term control, it is important to determine where the colony is located and what conditions are allowing it to remain established.
Professional Carpenter Ant Control
Effective carpenter ant control generally starts with identification and inspection.
A pest-control professional may look for:
- Active ant trails
- Nesting locations
- Frass
- Moisture-damaged wood
- Entry points
- Outdoor colonies
- Potential satellite colonies
- Areas where ants are repeatedly appearing
Treatment can then be selected according to the location and circumstances of the infestation.
Health Canada notes that established colonies may require the nest itself to be located and treated, and that professional assistance can be appropriate in difficult situations. Canada
Why Treating the Source Matters
One of the biggest mistakes homeowners can make is focusing only on the ants they can see.
The visible ants are often workers searching for food.
If the colony remains active, additional workers can continue to appear.
A comprehensive pest-management approach looks beyond the visible insects to determine:
Where are they coming from?
Where is the colony located?
Why are they entering the property?
Is moisture or damaged wood contributing to the problem?
Are there additional nesting areas nearby?
Addressing these factors can provide a more effective long-term solution.
Carpenter Ant Control in Cambridge, Kitchener, Waterloo & Surrounding Areas
Carpenter ants can become a frustrating problem for homeowners and businesses throughout Ontario.
GBG Pest Control provides professional pest-management services for homes and businesses, including ant control and other common pest problems.
Our approach focuses on identifying the pest, understanding the source of the activity, and using targeted treatment methods appropriate for the property.
GBG serves communities including Cambridge, Kitchener, Waterloo, Guelph, Milton, and Brantford. GGBG PEST
Seeing Carpenter Ants in Your Home?
Don’t assume that spraying the ants you see will solve the problem.
If carpenter ants keep appearing, you’re finding frass, or you suspect they may be nesting inside your walls, attic, roof, or other wooden areas, a professional inspection can help identify the source.
Contact GBG Pest Control at 519-222-7709 to discuss your carpenter-ant problem and arrange professional pest-control service.
GBG Pest Control — Protecting What Matters Most: Your Home, Your Business, Your Peace of Mind.