Identify the species first
| Trait | Norway rat (Rattus norvegicus) | Roof rat (Rattus rattus) |
|---|---|---|
| Body length | 20-25 cm | 16-20 cm |
| Tail vs body | Shorter than body | Longer than body |
| Activity level | Ground, crawlspace, basement | Attic, ceiling, upper walls |
| Droppings | 18-20 mm, blunt, capsule-shaped | 12-15 mm, slim, curved/pointed |
| Common entry | Crawlspace vents, foundation gaps, sewer laterals | Roof line, soffit gaps, dormer junctions, tree-canopy access |
| Most-affected Metro Van areas | Richmond delta, Strathcona, New West uptown, agricultural-adjacent Surrey/Maple Ridge | Vancouver west-side, Kitsilano, Burnaby Heights, North Vancouver, Steveston |
The full exclusion-first protocol
How to
Rat elimination protocol — Metro Vancouver
The protocol every Wild Pest tech follows for a confirmed rat infestation. Variant by species: roof rats add tree-canopy and roof-line work that Norway rats don't require.
- 1Confirm species + map activityWalk the perimeter and interior with a flashlight at dusk. Document every dropping site, every gnaw mark, every grease smudge. Photograph each. Determine species from droppings, runways, and activity height (ground vs ceiling). Roof rat investigations include attic and roof inspection.
- 2Inspect the structural perimeterNorway rats: foundation perimeter, crawlspace vents, utility penetrations, sewer line cleanouts, garage door bottoms, deck-to-house junctions. Roof rats: full roof inspection — gable vents, soffit-fascia gaps, ridge vents, dormer junctions, chimney flashing, tree-canopy contact points.
- 3Seal with industrial material19-gauge galvanised hardware cloth on every vent, with quarter-inch mesh maximum. Closed-cell foam packed with steel wool for utility penetrations. Aluminum flashing and drip-edge trim on roof junctions. Replace any soft weatherproofing with hard kit. Trim back tree branches that contact the roof for roof rats.
- 4Deploy bait stations + trapsTamper-resistant exterior bait stations along the foundation perimeter for Norway rats — 4-6 per typical lot, spaced 6-10 m. Interior snap traps at activity sites; bait stations indoors only in inaccessible voids. Roof rats: ceiling-level snap traps in attic, bait stations only if the attic has tamper-resistant placement options. SGAR-ban-compliant bait only.
- 5Monitor and revisit at weeks 2, 4, 8Refresh bait, check traps, re-inspect sealing. Norway rat activity drops 70% by week 4 with proper exclusion. Roof rat activity is slower to drop because the population can roam tree canopy when sealed out — plan for full eight-week monitoring.
What changed with the 2023 SGAR ban
On 21 January 2023, BC banned the residential use of second-generation anticoagulant rodenticides (SGARs) — brodifacoum, bromadiolone, difethialone, and difenacoum. These were the standard pest-control bait active ingredients for two decades because they kill in a single feeding. The ban was driven by secondary poisoning of raptors, owls, and household pets that consumed dying rats.
What replaced them: first-generation anticoagulants (chlorophacinone, diphacinone, warfarin) which require multiple feedings over several days to deliver a lethal dose, and non-anticoagulant alternatives like cholecalciferol and bromethalin. The result for homeowners: bait works slower, populations decline more gradually, and exclusion becomes proportionally more important. The pest-control industry shifted from 'bait-first' to 'exclusion-first' as a matter of regulatory necessity.
Why DIY rat control fails most of the time
- Most homeowners can identify some entry points but miss the high-elevation ones (roof returns, dormer junctions, second-floor utility penetrations) without specialist equipment.
- Snap traps work on naive juveniles; experienced adult rats avoid them after seeing a trapped sibling. Pros rotate trap types and locations to suppress this behaviour.
- Sealing materials matter — caulk lasts a season; hardware cloth and aluminum flashing last decades. DIY usually under-spec'd material.
- Without a follow-up at week 4 and week 8, the homeowner doesn't catch the second-generation rats emerging from undiscovered nests, and the population rebuilds.
- Roof rat work involves rooftop access and tree-canopy assessment — not safe for most homeowners and often missed entirely.
Frequently asked questions
How long until I stop hearing rats in my walls?+
With proper exclusion plus bait, ceiling and wall activity typically drops to zero within three to five weeks. Persistent activity past week six points to a missed entry point — re-inspect the high-elevation locations (roof returns, dormer junctions, gable vent perimeters) which are the most commonly missed.
Are dead rats in walls a real problem?+
Yes — but a manageable one. Most rats poisoned by anticoagulants travel back to their nest before dying, and most nests are in inaccessible wall, attic, or crawlspace voids. Smell lasts 2-4 weeks depending on temperature and ventilation. The smell is unpleasant but transient; the alternative (live rats breeding indoors indefinitely) is worse.
Why do my neighbours have rats but I don't?+
You probably do — you just haven't found the evidence yet. Rats migrate along blocks following food and water resources. Most Metro Vancouver streets have a baseline rodent presence year-round. The factor that determines indoor activity is the entry point density on your specific structure, not the neighbourhood.
Is rat poison safe around dogs and cats?+
Tamper-resistant bait stations are designed so dogs and cats cannot access the bait directly. Secondary poisoning from a dog eating a poisoned rat is the bigger risk, and that's why BC banned SGARs — the new first-generation anticoagulants have a much wider safety margin. We always discuss pet-safety protocol on the booking call before placing any bait.
Why are rats more common in certain neighbourhoods?+
Three factors: housing-stock age (pre-1980 stock has more entry points), waterway and agricultural adjacency (Richmond, Strathcona, Pitt Meadows), and tree canopy (West Vancouver, Burnaby Heights, North Van for roof rats). The municipality matters less than the specific block.