Every spring, as temperatures climb above 10°C, Ontario’s ants become active. While most species are merely annoying, Carpenter Ants (Camponotus pennsylvanicus) are a structural threat — I’ve seen homes with $15,000+ in wood damage from untreated infestations. Here’s how to protect your property.
1
Identify the Threat: Carpenter Ant vs. Common Ant
Carpenter ants are Ontario’s largest ant species (6–13mm), typically black or red-black. Crucially, they don’t eat wood — they nest in it, excavating smooth galleries in moist or decayed timber. The telltale sign: piles of fine sawdust-like material called frass near wood surfaces. If you find frass in your basement or attic, call a professional immediately.
2
Layer 1 & 2: Eliminate Food Sources & Seal Entry Points
Store all food in sealed containers — pet food, sugar, and honey are prime targets. Fix all plumbing leaks and maintain dry basements (Carpenter ants are attracted to moisture-damaged wood). Seal cracks in foundation walls, window frames, and where utilities enter. Remove firewood stored against the house exterior.
3
Layer 3: DIY Treatment Options
Ant bait stations (e.g., Terro, ~$8–12 at Home Depot) are far more effective than sprays. Worker ants carry the slow-acting poison back to the colony and queen — eliminating the source rather than just surface ants.
Diatomaceous Earth (food-grade) is a safe, non-toxic physical killer. Dust it along ant trails — the microscopic particles puncture the ants’ exoskeleton. Safe for pets and children once settled. Avoid inhaling the dust during application.
4
When to Call a Professional ($200–$500)
Call a licensed pest control company if:
you find frass (sawdust piles), you see large ants in your basement or attic in numbers, or DIY treatment shows no improvement after 2 weeks.
Cost reference: $200–$500 for single treatment; $600–$900 for multi-visit programs. When buying a home, ask your inspector to check basement beams and attic framing for frass and moisture-damaged wood — this is a legitimate negotiation item.
Home Buyer Checklist
During home inspection, ask specifically about: frass accumulation under basement beams, moisture readings in basement and crawlspace, and evidence of past ant damage to sill plates and floor joists. If found, request a professional pest report as a condition of your offer — treatment cost is negotiable.
AZ
Arthur Zhao
Broker · SRS · ABR · MCNE
📞 416-277-3836 · arthurzhao.realtor
#CarpenterAnts
#PestControl
#OntarioHomeowner
#HomeInspection
#SpringMaintenance
#DiatomaceousEarth
