A tenant calls to say there are mice in the kitchen. Or bedbugs. Or cockroaches. Your stomach drops — not just because of the cost, but because you're not sure whose problem this is and how bad it might get.
Here's what Ontario law says, and how to handle it practically.
The Legal Starting Point: Landlord Responsibility
Under Ontario's Residential Tenancies Act, landlords are required to maintain rental units in a good state of repair and comply with health, safety, and maintenance standards. The province's property standards — enforced by municipalities — almost universally require that rental units be free of pests.
The practical implication: pest control is generally the landlord's responsibility, regardless of how the infestation started. If your tenant reports a pest problem, you are expected to address it promptly with a licensed pest control professional.
This is true even if the tenant's behaviour contributed to the problem.
When Is It the Tenant's Fault?
Tenant behaviour can cause or worsen infestations — improperly stored food, excessive clutter, failing to report early signs of a problem. And yes, if a tenant's negligence is the direct cause of the infestation, you may be able to recover costs.
But — and this is important — you still have to fix the problem first. You can seek compensation through the Landlord and Tenant Board after the fact, but you cannot refuse to treat an infestation because you think the tenant is at fault, or use it as a pretext to withhold service.
The line between "landlord's responsibility" and "tenant's fault" is often blurry and disputed at the LTB. Document your evidence carefully if you intend to seek compensation.
Bedbugs: A Special Case
Bedbugs deserve their own section because they're among the most common and costly pest problems in Ontario rental properties — and they come with specific handling requirements.
What You Must Do
When bedbugs are confirmed (or even suspected):
Hire a licensed exterminator immediately. Bedbugs are notoriously difficult to eliminate without professional treatment. DIY approaches typically delay resolution and allow the infestation to spread.
Treat all affected units. In multi-unit buildings, bedbugs travel through walls, electrical conduits, and shared spaces. Treating only the unit where they were found almost always means retreating within weeks. A responsible exterminator will recommend treating adjacent units.
Provide proper notice before entry. Under the RTA, you must give 24 hours' written notice before entering for pest treatment (unless the tenant waives this). Keep records of all notices served.
Prepare the unit correctly. Pest control companies require tenants to prepare before treatment — clearing floors, laundering linens and clothing, vacating during treatment. Provide written preparation instructions from the exterminator directly to the tenant. If the tenant fails to prepare and treatment fails, that's documented evidence for cost recovery later.
Disclosure
In Ontario, landlords are required to disclose a current bedbug infestation to new tenants before signing a lease. Failing to disclose can result in an LTB application from the tenant.
There is no requirement to disclose a past infestation that has been resolved — though being transparent about what happened and how it was treated builds trust and avoids later disputes.
Mice and Rodents
Mice are particularly common in older housing stock in London, St. Thomas, and Sarnia, especially in fall and winter when they seek warmth. A single mouse in the unit does not always indicate a serious infestation — but it does require a response.
Steps to take:
- Hire a pest control company to assess entry points and set traps or bait stations
- Seal exterior gaps — mice can enter through openings smaller than a dime; steel wool and caulk are your friends
- Check the unit's foundation, utility penetrations, and garage door seals
If a tenant's food storage habits are contributing (open bags of food, garbage not properly managed), address that in writing — but don't use it as a reason to delay treatment.
Cockroaches
Cockroaches are less common in Southwestern Ontario than in larger cities, but they do occur — particularly in older apartment buildings and units that share walls. They require professional treatment and often need multiple visits.
As with bedbugs, tenant cooperation in preparation (clearing under sinks, emptying cupboards) is essential. Give written instructions from your exterminator and document whether the tenant complied.
What to Do When a Tenant Reports a Pest Problem
- Respond quickly — acknowledge the report in writing within 24 hours
- Arrange a professional inspection — don't rely on the tenant's description alone to scope the problem
- Book treatment promptly — delays allow infestations to worsen and give the tenant grounds for a rent reduction at the LTB
- Document everything — inspection reports, exterminator invoices, notices served, tenant preparation instructions
- Follow up — confirm the treatment worked; schedule a follow-up inspection if the exterminator recommends one
Rent Reduction and LTB Applications
If you fail to address a pest problem in a reasonable timeframe, tenants can file a T6 application (Tenant Application About Maintenance) with the Landlord and Tenant Board. The LTB can order you to complete the repairs, reduce rent retroactively to the date the problem was reported, and award other remedies.
The LTB takes maintenance failures seriously. A documented and swift response — even if the problem takes multiple treatments to resolve — is far better than doing nothing.
Prevention Is Cheaper Than Treatment
Bedbug and rodent treatments can run from a few hundred to several thousand dollars depending on the scope. Prevention costs far less:
- Annual exterior inspections to seal gaps and entry points
- Clear communication with tenants about garbage handling and food storage
- Prompt response to early reports before problems spread
Prospera Properties includes pest prevention in our regular property inspections, and we coordinate professional treatment whenever needed — so landlords don't have to manage exterminators and tenant communication on their own. It's one of those issues that's much easier to handle when you have a system.
No landlord wants to deal with pests. But handling them quickly, professionally, and with proper documentation is what separates a manageable problem from an LTB hearing.