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Termite control is regulated work. A licensed exterminator confirms the activity, treats the soil or the colony, and works with the owner to remove what lets termites reach the wood: moisture, buried lumber and wood touching the ground. Some towns also have a bylaw or an area program, so treatment is often coordinated with the municipality and the neighbours rather than handled one house at a time.
This page covers how to recognize termites, how they differ from carpenter ants, what draws them in, how treatment works, municipal programs and what to check when buying in an affected area.
Eastern subterranean termites in Ontario: how the colony lives and feeds
Guelph reports that the eastern subterranean termite arrived in Ontario accidentally from the United States and has reached more than 30 municipalities, and Toronto says the insect has been in the city since 1938 and is now established in homes across it. Outside those communities termite damage is uncommon, which is why local knowledge matters as much as the insect itself.
Unlike insects that nest inside the house, this termite keeps its nest underground and travels up to its food. The City of Toronto explains that termites build tubes from the ground to the wood they are eating, and that they feed on dead wood rather than healthy trees. In a house, that food is sill plates, joists, basement stairs, door frames and anything else made of wood or paper that workers can reach from the soil.
Signs of termites in a house: mud tubes, hollow wood and blistered trim
Termite activity is easy to miss because the insects avoid light and open air. Check basements, crawl spaces and garages, and walk the outside of the foundation, paying most attention to places where wood is close to the soil.
- Narrow, earth-coloured mud tubes running up foundation walls, piers, basement posts or the sides of steps from the soil to wood.
- Wood that sounds hollow or dull when tapped, especially sill plates, joists and basement framing.
- Galleries inside the wood that follow the grain and are packed with soil-like material.
- Blistered, rippled or sagging paint, and baseboards or door frames that feel soft.
- Winged termites or small piles of shed wings on window sills or near the foundation.
- Damage to cardboard boxes, paper or lumber stored directly on a basement floor.
Termite damage vs carpenter ant damage: how to tell them apart
Both insects damage wood in Canadian houses, but the treatment is different, so identification has to come before any quote. A licensed exterminator can confirm the species, and a few clues help you describe what you are seeing.
- Termite galleries are packed with a mix of soil and droppings, while carpenter ant galleries are smooth and clean.
- Carpenter ants push coarse, sawdust-like debris out of their galleries, while termites leave no sawdust piles.
- Termites build mud tubes to reach wood from the soil, while carpenter ants travel in the open and are often seen foraging.
- Winged termites have straight bodies and wings of equal length, while winged ants have pinched waists and larger front wings.
- Carpenter ants excavate wood to nest but don't eat it, while termites feed on the wood itself.
Moisture and wood-soil contact: the conditions that let termites into a house
Subterranean termites depend on moisture and a connection to the soil, so the houses they reach are usually the ones that offer both. Toronto's forestry guidance names breaking the contact between wood and soil as a key step, and the same logic applies to a house: termites that must build tubes across bare concrete are much easier to spot. These are the conditions an inspector looks for.
- Wood siding, trim, lattice, deck posts or stair stringers that touch the soil or sit below grade.
- Firewood, lumber and old stumps stored or left against the foundation.
- Leaking gutters, downspouts that empty at the foundation and grading that slopes toward the house.
- Damp basements and crawl spaces, and plumbing leaks that keep framing wet.
- Wood mulch piled high against the foundation wall.
- Cracks in the foundation or slab and gaps around pipes that give tubes a hidden path indoors.
Professional termite treatment in Ontario: licensed exterminators and treatment options
Termite control is not a do-it-yourself job. In Ontario, applying pesticides for hire on property you don't own requires an exterminator licence, and the province's licensing guide includes a termite class of structural exterminator licence for preventing or controlling termites. Quebec also requires a provincial certificate for commercial pesticide use. Ask which licence the technician holds before work starts.
- An inspection maps active tubes, damaged wood, moisture problems and the likely route from the soil into the house.
- Soil treatment places a termiticide in the ground along the foundation and around entry points to stop termites reaching the structure.
- Bait stations set in the soil around the house hold a slow-acting product that foraging termites carry back to the colony.
- Infested wood and cellulose debris are removed, and the moisture and wood-soil problems are corrected.
- Damaged framing is assessed and repaired by a qualified contractor, with an engineer involved when load-bearing members are weakened.
- Follow-up inspections confirm whether activity has stopped and catch any return early.
Municipal termite control bylaws and programs: Guelph, Toronto and other Ontario towns
Because one colony can forage under several lots, some municipalities treat termites as a neighbourhood problem. Guelph continues to enforce the Ontario Building Code and its Termite Control Bylaw on a property-by-property basis where needed, and it is working with property owners in the Regent Street and Grove Street area to manage termite activity. It also asks residents to manage wood in their yards and to bring infested wood to its Waste Resource Innovation Centre for disposal.
Toronto's guidance for termite-affected trees recommends removing trees that are structurally unsound, pruning out the dead wood termites feed on, breaking wood-soil contact and consulting professionals about chemical treatment. Other towns with a termite history set their own rules, so check your municipality's website or call its building department before planning treatment or a renovation.
Buying a home in a termite area: disclosure, treatment records and guarantees
Guelph recommends that sellers in affected areas tell prospective buyers about any known termite activity and consider an inspection by a licensed termite inspection company. As a buyer, make your offer conditional on a termite inspection, ask the seller for treatment invoices and any guarantee, and find out whether the street is in an area the municipality has monitored or treated.
- Ask when the last treatment was done, which method was used and whether the guarantee transfers to a new owner.
- Ask your home inspector to note mud tubes, damaged wood and wood-soil contact, and bring in a termite specialist if anything turns up.
- Look closely at finished basement walls, basement framing and the base of stairs, where damage stays hidden.
- Leave room in your conditions for a structural assessment if damaged wood is found.
Preventing termites after treatment: yard and foundation habits
- Keep a visible gap between the soil and any wood siding, trim or framing, and replace wood that has rotted at grade.
- Store firewood and lumber off the ground and away from the house.
- Remove stumps, buried construction scraps and dead branches from the yard.
- Keep gutters and downspouts working and the grade sloping away from the foundation.
- Leave the lower part of the foundation wall visible so tubes can be spotted during a seasonal walk-around.
- Use concrete, metal or ground-contact rated materials where posts and structures meet the soil.
- Keep up the monitoring visits or bait-station checks in your treatment agreement.
Termites: frequently asked questions
How do I know if termites are a problem in my town?
Start with your municipality. Towns with a termite history, such as Guelph and Toronto, publish information about the insect and any bylaw or program, and neighbours who have had treatment and local licensed exterminators know which streets have seen activity.
Can I treat termites myself?
Effective treatment involves soil or colony treatment that, in Ontario, falls under a termite exterminator licence. What you can do yourself is fix leaks, move wood away from the foundation and watch for mud tubes.
Should I break the mud tubes I find?
Leave them until the exterminator has seen them. The tubes show where termites are travelling and whether they are active, which helps decide where treatment goes. Photograph them and note where they are.
Do termites mean my house is structurally unsafe?
Not necessarily, but it needs checking. The exterminator can show where the damage is, and a contractor or engineer should assess any weakened beams, joists or sill plates before repairs begin.
Are termite treatments safe for my family and pets?
Health Canada regulates pest control products and the conditions for their use, and a licensed exterminator must follow the label. Ask for the product name, how long to keep off treated areas and any precautions for children and pets.
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Written by the LokalMatch editorial team. Reviewed by Zubair Afzal on September 10, 2026. How we write and check our guides