Ants in Your Home: Common Ontario Ant Species, Damage Risks, and How to Prevent an Infestation

Written By Corey Dejong

Finding ants inside your home can be frustrating. While a few ants in the kitchen may seem like a minor nuisance, an ant infestation can quickly become a larger problem. Some species are simply looking for food, while others can damage your home’s structure and indicate hidden moisture issues.

Ontario homeowners commonly deal with several types of ants, including pavement ants, odorous house ants, and carpenter ants. Understanding the type of ant you have is the first step toward effective prevention and removal.

Why Are Ants Coming Into Your Home?

Ants enter homes for a few main reasons:

  • Searching for food sources such as sugar, crumbs, pet food, and garbage

  • Looking for water, especially during dry weather

  • Seeking shelter from extreme temperatures

  • Establishing nests in wall voids, insulation, soil, or damaged wood

Ants are social insects that live in colonies. When you see a line of ants moving through your home, they are usually following a scent trail created by worker ants. Once one ant discovers a food or water source, others will follow.

The Most Common Ants Found in Ontario Homes

Carpenter Ants

Carpenter ants are one of the most concerning ants found in Ontario homes. Unlike termites, carpenter ants do not eat wood, but they tunnel through it to create nesting galleries. Over time, these tunnels can weaken damaged or moisture-affected wood.

Carpenter ants are commonly found in:

  • Moist or rotting wood

  • Window and door frames

  • Roof areas

  • Wall voids

  • Tree branches touching the home

  • Decks and fences

Signs of carpenter ants include:

  • Large black ants inside your home

  • Small piles of sawdust-like material (called frass)

  • Ant activity near windows, doors, or damp areas

  • Rustling sounds inside walls (in severe cases)

Carpenter ants are most active in spring and summer, making warmer months the ideal time for homeowners to inspect their properties.

Odorous House Ants

Odorous house ants are one of the most common indoor ants in Ontario. They are small, usually dark brown or black, and are often found travelling in long trails.

They are attracted to:

  • Sweet foods

  • Spilled drinks

  • Kitchen counters

  • Pet food bowls

  • Garbage areas

These ants get their name from the unpleasant smell they release when crushed, often described as a rotten coconut-like odor.

Although they typically do not cause structural damage, odorous house ants can quickly become a persistent indoor pest problem because colonies may contain thousands of ants.

Pavement Ants

Pavement ants commonly nest outdoors under:

  • Driveways

  • Sidewalks

  • Patios

  • Foundation cracks

  • Concrete slabs

They often enter homes through small cracks and gaps in foundations, doors, and windows.

Pavement ants are usually attracted to food sources indoors and are commonly seen in kitchens, bathrooms, and basements.

Pharaoh Ants

Pharaoh ants are small yellowish or light brown ants that are less common in typical homes but can be challenging to eliminate. They are often found in warm indoor environments such as:

  • Apartments

  • Commercial buildings

  • Healthcare facilities

Pharaoh ants can create multiple colonies, making improper treatment methods ineffective and sometimes causing the infestation to spread.

The Most Destructive Ant in Ontario: Carpenter Ants

While most ants are considered a nuisance, carpenter ants are the species homeowners should take most seriously.

Carpenter ants prefer damp or damaged wood because it is easier to tunnel through. They often indicate an underlying moisture problem such as:

  • Leaking roofs

  • Poor drainage

  • Damaged siding

  • Plumbing leaks

  • Rotting exterior wood

A carpenter ant infestation does not usually destroy a home as quickly as termites, but years of tunnelling can contribute to structural deterioration if left untreated.

How to Prevent Ants Around Your Home

The best way to deal with ants is to prevent them from entering in the first place.

1. Seal Entry Points

Inspect your home’s exterior and seal:

  • Foundation cracks

  • Gaps around windows and doors

  • Openings around utility lines

  • Spaces under siding

Ants can enter through extremely small openings, so regular exterior inspections are important.

2. Remove Food Sources

Keep ants from being attracted to your home by:

  • Cleaning spills immediately

  • Storing food in sealed containers

  • Keeping countertops clean

  • Emptying garbage regularly

  • Cleaning pet food areas

Even small amounts of sugar or grease can attract large numbers of ants.

3. Control Moisture Around Your Home

Moisture attracts many ant species, especially carpenter ants.

Homeowners should:

  • Repair leaks quickly

  • Keep gutters clean

  • Direct downspouts away from the foundation

  • Remove standing water

  • Replace damaged wood

Reducing moisture makes your home less attractive for nesting.

4. Maintain Your Landscaping

Outdoor conditions can contribute to indoor ant problems.

Consider:

  • Keeping tree branches and shrubs away from the house

  • Removing old stumps and decaying wood

  • Keeping mulch away from the foundation

  • Storing firewood away from exterior walls

How to Get Rid of Ants in Your Home

Identify the Ant Species First

Different ants require different treatment methods. Spraying visible ants may kill workers but often does not eliminate the colony.

The colony, queen, and nesting areas must be addressed for long-term control.

Use Ant Baits Carefully

Ant baits can be effective because worker ants carry the bait back to the colony. However:

  • Avoid spraying ants that are actively taking bait

  • Place baits near trails and entry points

  • Give the bait time to work

Keep in mind that retail baits may not be effective enough. The benefit of an exterminator is licensed access to higher quality bait.

Clean and Remove Trails

Ants rely on scent trails to navigate. Cleaning areas where ants travel can reduce activity.

Use:

  • Soap and water

  • Household cleaners

  • Vinegar solutions

This removes the pheromone trails that guide other ants.

When to Call a Professional Pest Control Company

Professional treatment may be necessary when:

  • Ants continue returning after DIY treatments

  • Carpenter ants are found inside

  • There are signs of damage to wood

  • The nest cannot be located

  • Ant activity is widespread

A professional can identify the species, locate nesting areas, and develop a treatment plan designed for the specific infestation.

Protect Your Ontario Home From Ant Infestations

Ants may be small, but they can create significant problems for homeowners. From nuisance species like odorous house ants to potentially damaging carpenter ants, early identification and prevention are key.

Regular home inspections, moisture control, sealing entry points, and proper treatment methods can help keep ants outside where they belong.

If you are dealing with persistent ants in your home, especially carpenter ants, addressing the problem early can help prevent larger issues and protect your property.

Corey Dejong
Next

Hantavirus in the Headlines: How to Protect Your Home and Family from Rodent Exposure