What size gap can a mouse get through?

A mouse needs only 6mm of space to enter your home. This is about the width of a pencil. A rat needs 20mm, roughly the width of a quarter.

What is the number one rodent entry point in GTA homes?

The gas line penetration where it enters the exterior wall. This gap is rarely sealed properly during construction and is the most common mouse entry point in GTA homes.

Can I use expanding foam to seal rodent gaps?

Never use expanding foam alone. Mice and rats chew right through it. Always stuff gaps with steel wool first, then seal with silicone caulking over the steel wool.

Should I seal gaps inside or outside?

Seal both. Mice can enter from outside, but they also travel between rooms. Seal the exterior first, then address interior gaps between the garage and living spaces.

What about the garage door?

Check the seal along the bottom and sides of your garage door. Even a small gap at the corners or a broken spring gap allows rats and mice to enter. Install a garage door threshold seal.

The Complete Rodent-Proofing Checklist for GTA Homeowners

By PestRecord Editorial Team

Exclusion is the most effective form of rodent control. Here is every gap to check on your GTA home and how to seal each one correctly.

The Golden Rule

A mouse needs only 6mm of space to enter your home. A rat needs 20mm. Think of it this way: if a pencil fits in the gap, a mouse fits too. Never assume a small gap is too small.

Also, never use expanding foam alone. Mice chew right through it within days. The correct method is steel wool stuffed into the gap, covered with silicone caulking.

Foundation and Exterior

Check these areas around your entire foundation: gaps where gas, water, and electrical lines enter the home (the gas line is the number one mouse entry point in GTA homes), cracks in the foundation wall, gaps around basement windows and window frames, spaces where dryer vent pipes exit through the wall, and gaps where HVAC pipes penetrate exterior walls.

Seal all of these with steel wool and silicone caulking.

Garage

Inspect the garage door seal along the bottom and sides. Many GTA homes have broken seals or spring gaps at the corners. Install a rubber garage door threshold seal. Check that the service door that connects your garage to your home seals tightly.

Doors and Windows

Install door sweeps on all exterior doors, especially the door between the garage and the house. Check window frames for gaps and seal with caulking. Make sure window screens have no holes.

Roofline and Attic

Check soffit vents for gaps and damaged screens. Inspect roof penetrations where satellite dishes, vents, and chimneys exit the roof. Look for gaps in the fascia board along the roofline. These areas are common rat entry points.

Interior Gaps

Seal gaps between the garage and living space, around pipes under kitchen and bathroom sinks, and where pipes enter walls in the basement. Mice travel between rooms using these pathways.

Complete rodent proofing for a typical GTA home takes a full afternoon or a professional inspection visit. Get free quotes from licensed mouse control operators or rat control operators for a thorough inspection and professional exclusion service.