Why mouse infestations are landlord responsibility
Mouse infestations in BC rental units are driven by structural entry points — gaps in the foundation, worn soffit trim, unsealed utility penetrations, aged weatherstripping — and building age. Neither of these conditions is the tenant's responsibility to create or maintain. The permanent fix is structural exclusion (sealing entry points with industrial materials) plus population suppression; both of these are landlord-scope work under RTA Section 32. Tenant fault would require something like deliberately attracting mice or refusing to clean to a degree that materially exceeds reasonable occupancy — both rare and difficult to prove at RTB. In more than 95% of Metro Vancouver mouse cases, the entry point is a structural gap that predates the current tenancy.
How to identify active mouse activity
Before contacting your landlord, spend five minutes confirming you have mice rather than another pest. House mice (Mus musculus) leave distinctive evidence: droppings that are 3–6 mm long, dark brown to black, granular, and pointed at both ends — about the size and shape of an apple seed. They appear along wall edges, inside cabinets (especially lower kitchen cabinets near food), behind appliances, in basement utility areas, and inside storage boxes. Greasy 'rub marks' along baseboards are another sign — mice travel the same routes repeatedly and leave body-oil smears on frequently used surfaces. You may also hear scratching in walls, typically at night (mice are most active between midnight and 4 AM), and occasionally find small gnaw holes in food packaging or cardboard.
What you can do immediately
- Document everything with photos: droppings (with a coin for scale), live mice if seen, gnaw marks on food packages, and any damaged belongings. Note date and location in the photo's caption or in a log.
- Send written request to landlord: 'Mouse droppings found in [location] on [date]; requesting professional pest control inspection and treatment per RTA Section 32.' Use email or text for the paper trail. Attach one clear photo.
- Deploy snap traps in dropping areas and food-storage zones while waiting. Tenant-side suppression with snap traps is reasonable interim action — bait with peanut butter, set against walls (mice run along edges), check daily.
- Seal interior access gaps with steel wool packed into holes, then closed-cell foam over the wool. Under-sink pipe penetrations, behind appliance power cords, around HVAC supply boots in the floor. Exterior structural sealing remains landlord scope — but interior gap sealing is tenant-accessible and reduces activity while waiting.
- Store all food in sealed hard containers (not just plastic bags — mice chew through them). Remove pet food bowls overnight. Seal trash in a lidded container.
- Save all communications with landlord — screenshot texts, save email threads. Never rely on phone calls alone.
When to escalate to RTB
If the landlord doesn't respond to your written request within 7 days, send a follow-up referencing RTA Section 32 and stating you will file with the RTB if no action is arranged within 7 more days. If there is still no response or action: file a Notice of Dispute with the Residential Tenancy Branch. The RTB can order treatment, order rent reduction for the period of diminished use, and order compensation if landlord delay caused damage to tenant property. For mouse infestations that have damaged food, clothing, electronics, or structural elements of the unit, document those losses with photos and a cost estimate.
What Metro Vancouver housing types are most affected
Basement suites in pre-war character homes (East Van, Kitsilano, New Westminster, South Burnaby) have the highest mouse-entry-point density of any Metro Vancouver rental stock. Original foundation concrete has settled and cracked; original wood-framed crawlspace vents have aged beyond their seal life; knob-and-tube electrical chases were never sealed when upgraded. A thorough exclusion of a 1930s East Van character home can involve 20–35 individual seal points. Mid-century rental apartments (1950s–1970s, common in Burnaby, Richmond, and Surrey City Centre) have utility-penetration gaps that weren't sealed to modern standards during construction. Strata condos typically have lower mouse pressure because they have sealed concrete construction — but mice can enter through utility chases and travel between units once inside. See also [cockroaches in your apartment building](/guide/cockroaches-rental-building) for multi-unit pest migration context.
What a professional mouse treatment includes
- Full-perimeter inspection documenting every entry point with photos — your landlord receives a written report.
- Exterior structural exclusion: stainless-steel mesh wool in utility penetrations, closed-cell foam overlay, hardware cloth at crawlspace vents.
- Interior tamper-resistant bait stations at all activity sites, against walls, checked at 2-week intervals.
- Monitor and re-inspect at weeks 2, 4, and 6 — confirm zero activity before sign-off.
- Photo report delivered within 30 minutes of service completion — documentation for landlord and tenant files.