Norway Rats vs Roof Rats: What Threat Does Each Pose to Your Montreal Property?

Montreal is home to two main rat species, each with distinct behaviours and habitat preferences. Understanding the differences between Norway rats and roof rats is crucial for effective control. ExtermExpress provides expert rodent control tailored to the specific species infesting your property.

Norway Rats (Brown Rats)

Identification

• Size: Large, 20-27cm body plus 15-22cm tail
• Colour: Brown to grey-brown with a lighter belly
• Build: Heavy, stocky body
• Ears: Small relative to body size
• Tail: Shorter than body length

Behaviour

• Ground dwellers: Prefer basements, sewers, and ground-level areas
• Burrowers: Dig extensive tunnel systems along foundations
• Swimmers: Excellent swimmers, can enter through sewer pipes
• Nocturnal: Most active at night
• Cautious: Neophobic — suspicious of new objects in their environment

Risks to Your Property

• Burrow under foundations, potentially causing structural damage
• Contaminate food stores with droppings and urine
• Gnaw through pipes, wires, and building materials
• Can transmit diseases including leptospirosis and salmonella
• Enter through sewer connections and floor drains

Roof Rats (Black Rats)

Identification

• Size: Smaller, 15-22cm body plus 18-25cm tail
• Colour: Dark brown to black with a lighter belly
• Build: Sleek, slender body
• Ears: Large relative to body size
• Tail: Longer than body length

Behaviour

• Climbers: Excellent climbers, prefer elevated areas
• Aerial routes: Travel along power lines, tree branches, and rooflines
• Nest high: Prefer attics, rafters, and upper floors
• Agile: Can jump up to 1 metre vertically
• Less common in Montreal: But present, especially near port areas

Risks to Your Property

• Damage roof structures, insulation, and stored items in attics
• Chew electrical wiring, creating fire hazards
• Contaminate attic spaces with droppings and urine
• Can transmit diseases
• Enter through roof vents, gaps in soffits, and tree branches touching the roof

Control Strategies

For Norway Rats

• Seal foundation cracks and gaps around pipes at ground level
• Install one-way valves on floor drains
• Remove ground-level harbourage (debris, woodpiles)
• Use ground-level bait stations and traps
• Address sewer connections

For Roof Rats

• Trim tree branches away from the roof (at least 1.5 metres)
• Seal gaps in soffits, roof vents, and eaves
• Install chimney caps
• Use elevated bait stations and snap traps
• Remove climbing routes (vines on walls, adjacent structures)

For Both Species

• Eliminate food sources (secure garbage, don't leave pet food out)
• Remove water sources
• Reduce clutter and harbourage areas
• Regular professional monitoring

When to Call a Professional

Call ExtermExpress immediately if you notice:

• Rat droppings (larger than mouse droppings — about 12-18mm)
• Gnaw marks on wood, wires, or food packaging
• Burrows along foundations or in the yard
• Scratching sounds in walls, ceilings, or under floors
• Grease marks along walls and baseboards
• Actual rat sightings (seeing one usually means many more are present)

Conclusion

Whether you're dealing with Norway rats in your basement or roof rats in your attic, professional intervention is essential. Rats reproduce quickly and can cause significant damage. ExtermExpress identifies the species, implements targeted control strategies, and prevents future infestations.