In Ontario and BC, the headline structural pest isn't the termite, it's the carpenter ant. They don't eat wood; they excavate smooth galleries in it and throw the shavings out as frass (fine sawdust piles). Health Canada's own guidance makes the point that matters for buyers: carpenter ants indoors prefer moist, decaying wood, they're a moisture finding with legs.
$300 to $800 carpenter-ant treatment (complex $1,000+); the moisture source is the real costAddress soonStructureInterior
The quick answer
In Ontario and BC, the headline structural pest isn't the termite, it's the carpenter ant. They don't eat wood; they excavate smooth galleries in it and throw the shavings out as frass (fine sawdust piles). Health Canada's own guidance makes the point that matters for buyers: carpenter ants indoors prefer moist, decaying wood, they're a moisture finding with legs.
The ants are treatable for a few hundred dollars. The wet wood they moved into is the real finding, a plumbing leak, a leaky deck ledger, a roof drip. Treating the ants without fixing the moisture is renting a solution. Rodents matter for a different reason: they chew wiring insulation (a fire risk worth an electrical cross-check) and contaminate attic insulation.
How to spot it
Frass piles below baseboards, window frames, or deck posts; large black ants indoors in cold months (a colony inside the structure, not summer foragers); smooth, clean galleries in any exposed damaged wood (vs. the mud tubes of termites). For rodents: droppings along basement walls and garage edges, gnawed wires, chewed soffit vents.
What it costs
Ontario carpenter-ant treatment runs $300 to $800 (complex, multi-visit jobs $1,000+); general ant control in Toronto ~$225 to $425. Rodent exclusion and cleanup $300 to $2,000. Structural repair depends on what the moisture did.
What to do
Address soon, and ask the better question: not "any pests?" but "any carpenter ants, and where was the moisture?"
Education and triage, not a home inspection. Casaroo flags frass, droppings, and damage from your photos and points at the moisture question. A licensed pest professional confirms and treats.
Common questions
What is Carpenter ants, rodents & household pests?
In Ontario and BC, the headline structural pest isn't the termite, it's the carpenter ant. They don't eat wood; they excavate smooth galleries in it and throw the shavings out as frass (fine sawdust piles). Health Canada's own guidance makes the point that matters for buyers: carpenter ants indoors prefer moist, decaying wood, they're a moisture finding with legs.
Why does it matter for home buyers?
The ants are treatable for a few hundred dollars. The wet wood they moved into is the real finding, a plumbing leak, a leaky deck ledger, a roof drip. Treating the ants without fixing the moisture is renting a solution. Rodents matter for a different reason: they chew wiring insulation (a fire risk worth an electrical cross-check) and contaminate attic insulation.
How can I spot it?
Frass piles below baseboards, window frames, or deck posts; large black ants indoors in cold months (a colony inside the structure, not summer foragers); smooth, clean galleries in any exposed damaged wood (vs. the mud tubes of termites). For rodents: droppings along basement walls and garage edges, gnawed wires, chewed soffit vents.
How much does it cost to fix?
Ontario carpenter-ant treatment runs $300 to $800 (complex, multi-visit jobs $1,000+); general ant control in Toronto ~$225 to $425. Rodent exclusion and cleanup $300 to $2,000. Structural repair depends on what the moisture did.
Last reviewed 2026-07-10.
This guide is general education, not a home inspection and not advice for your specific property. Always
consult the appropriate licensed professional, and get a licensed home inspection before you remove conditions
or buy. Cost ranges are 2026 estimates that vary by region, size, and access; confirm specifics with a
qualified professional.