Galvanized steel mesh exclusion foundation

Case Study: Rat Extermination in Old Toronto

The following article details an interior and exterior rat extermination in Old Toronto. Rats were found burrowing into a single-family home and removed with a combination of rodenticide, traps, and pest-proofing. If you are struggling with a rat problem on your property, please reach out to the experts at The Exterminators.

Old Toronto: Toronto’s Historic Downtown

Old Toronto refers to the former City of Toronto prior to the 1998 amalgamation of the surrounding cities of Scarborough, York, North York, and Etobicoke. It was originally called the town of York and belonged to York County.

old Toronto city hall

It was renamed Toronto in 1834, when it was first incorporated, to distinguish it from New York City.

Prior to amalgamation, the city of Toronto had annexed the town of Brockton, the town of Parkdale, and Swansea as well as Yorkville, the Annex and Seaton Village to the north.


The homeowner in this case called to inform us that rats had been present in his home and may have entered through a crack on the wall. We assured the customer that we would get rid of the rodents, but first need to do a full inspection and determine what work need to be done.

We dispatched one of our skilled licensed exterminators to gauge the depth of the problem and decide on the best way to approach it.

We began with a full inspection of the exterior of the home to determine where the point of entry was located. Our technicians are trained to pinpoint any possible entry point into the structure. The property is also evaluated for ongoing rat activity. The higher the activity seen in yards, the more likelihood the rodents will infiltrate the home in search of food or a nesting place.

At this home, the technician discovered some large cracks and gaps in the foundation wall under the front porch.

Cracked Foundation Rat Entry Point

Indoors, most of the activity was taking place in the basement near the front of the house. This is consistent with the outside entry point location. Fecal matter was found throughout the area suggesting the rats may have been present for an elongated period of time.

Initial Steps

As an immediate action plan, our technician placed snap-traps inside the home in the areas of rodent activity. These traps are baited with either peanut butter or bacon and are highly effective in quickly killing any rats inside the home. The homeowner was advised that to prevent the rodents from becoming permanent tenants in their home, we would need to create a barrier under the front porch. This tactic, called an exclusion, is often enough to shield the home from further infestations. A part of our initial steps taken 2 exterior rodent bait stations we installed on the home’s exterior.

Rat Snap Traps
Snap Traps are effective for reducing the rat population indoors. These can be cleaned and used again until the rats are gone.


Our team returned to perform the exclusion work under the front porch. This was done by digging a small trench along the foundation wall and then installing a stretch of galvanized steel mesh that is secured to the wall and to the ground. This commercial grade mesh is durable and strong enough to withstand any gnawing from rodents.

Galvanized steel mesh exclusion foundation

The mesh is bent outwards beneath the ground to prevent the rats from burrowing deeper and underneath the mesh.

Rat Proofing Mesh Exclusion

To control the rats roaming outside the house we placed a few bait stations filled with a commercial-grade rodenticide. This extermination process usually needs time and patience as the rats will need to take to the rodenticide a few times before it takes effect. Our team will visit the location regularly to re-fill these bait stations.


Rodents can be quite destructive when inside a house. They will create tunnels through insulation, gnaw through electrical wiring, defecate behind walls, etc. If they create a nest inside a home, the problem becomes exponential and extermination will be much more difficult to conduct.

This homeowner acted quickly, and we were able to identify, eliminate, and prevent further issues. Visible entry points were blocked permanently, giving our customers peace of mind.

Our exclusion work is backed by a 2-year warranty. Should the rodents manage to penetrate through any of our installations, we will return to repair or replace any or all our work.