Undisclosed Pest Infestations After Buying a Home in Ontario: What Buyers Can Do

You move into your new home expecting a fresh start, not evidence of bedbugs behind the baseboards or termite damage in the foundation. When a pest problem surfaces shortly after closing, the first question is usually: did the seller know, and if so, why didn't they say anything?

Undisclosed pest infestation disputes in Ontario turn almost entirely on what the seller actually knew and when. A pest problem the seller genuinely didn't know about is treated very differently from one they were actively dealing with before listing the home.

This article covers how to tell the difference, what to do right away, and what legal options may be available.

When a Pest Problem Crosses Into "Should Have Disclosed" Territory

Ontario's default rule for resale purchases is caveat emptor, so a seller generally isn't obligated to volunteer every issue with a property. That default shifts when the seller actually knew about a serious infestation — particularly one affecting the structure or safety of the home, such as termite damage — and stayed silent or actively concealed it.

A pest problem that's purely cosmetic or minor is treated differently than one causing genuine structural or habitability concerns.

Signs the Seller May Have Known

• [ ] Fresh paint, caulking, or patchwork concentrated in specific areas, especially baseboards, window frames, or foundation walls
• [ ] Pest control invoices, contracts, or treatment records found in leftover paperwork or utility drawers
• [ ] Strong odours (cleaning products, pesticides) noticeable only in certain rooms during showings
• [ ] Furniture or boxes unusually positioned against walls or in corners during your viewings
• [ ] A Seller Property Information Statement that answered "no" to a pest-related question

None of these alone prove concealment, but together they can support an inference that the seller was aware of the problem.

What to Do the Moment You Discover It

1. Document everything before you treat or repair anything. Photos, video, and a written description of exactly what you found and where.
2. Get a professional pest inspection report identifying the type of infestation, its extent, and — where the inspector can assess it — how long it's likely been present.
3. Preserve the physical evidence where possible, rather than immediately demolishing or discarding affected materials.
4. Review your Agreement of Purchase and Sale and any SPIS for relevant representations or warranties.
5. Speak with a real estate lawyer before you spend significantly on remediation, so you understand how repair costs interact with any potential claim.

Legal Remedies to Consider

• Misrepresentation — if the seller made a false statement about the property's condition, including through an SPIS
• Breach of a specific contractual warranty — if your Agreement of Purchase and Sale included a representation about pest-free condition or similar
• A claim tied to active concealment — if there's evidence the seller took steps to hide signs of the infestation, such as covering damage rather than repairing it

The strength of any claim depends heavily on the evidence of the seller's actual knowledge, not just the existence of the infestation itself.

The Role of Your Home Inspection

If your own pre-purchase inspection didn't flag the issue, that's not automatically a problem for your claim — some infestations, particularly structural pests like termites, can be genuinely difficult to detect without invasive testing. But it's worth asking your inspector whether the signs were visible at the time, since that assessment can cut either way in a dispute.

Frequently asked questions