Galvanized-Steel Mesh-Installation

Case Study: South Riverdale Rat Control and Exclusion

This article will analyze and recount an extensive rat problem our team had to deal with. The extermination case required multiple visits as rats had burrowed underground and under the foundation. The case study  details the steps we took to bring this rat pest control problem under control. It also details how the exclusion we installed to eradicate the rat presence completely and successfully in a residential property in South Riverdale, Toronto.

Technicians go through several steps to conclude before moving on to the actual exclusion and the eventual sealing and proofing. We received word from the property owner of possible rodent activity taking place in the crawl space of the property.

South Riverdale: Toronto’s bustling historic neighborhood

South Riverdale is marked by its multi-ethnic communities that call the Riverdale area their home. Enclaves of Greeks and Chinese have added to its prominence. Riverdale in its entirety is bounded by the Don River and is one of the historical neighborhoods and areas in Toronto. The architecture goes back at least to the 18th CE in which older houses are located. It has  an innumerable selection of ethnic restaurants, cafes, and stores in the neighborhood which makes the area very attractive for wildlife and rodents to roam around in. Homes that are older have been more susceptible to structural damage. The structural damage along the perimeter of these properties can give a host of rodents the opportunity to exploit cracks, holes, and crevices. Older pipes that are into disuse can lead these rats to the interior of these properties and give them a safe space to breed and to spawn future generations without any detection until it is too late as we will see in the following case.  Rat problems in Riverdale are nothing new.

Riverdale Rat Problems


Exterior Inspection

The property owner of residential property in the South Riverdale neighborhood had concerns of rodent activity taking place in the crawl space. The technician set out to conduct an exterior inspection. The exterior inspection is one of the most essential parts of permanently keep the rats out of the home. The exterior inspection is meant to detect rodent activity outside the property as well as finding possible entry-points that give access to the rodents to the interior of the property. The technician meticulously and carefully looks for any trace of rodent activity. These clues can include but are not limited to droppings, gnaw marks, bite marks, scattered material, tracks, and finding a nest. All of these clues can point to active rodent presence on the outside exterior. If any of these signs are found, the technicians will inform the property owner and will recommend taking any next step.

Interior Inspection

The interior inspection  also plays an essential role in regards to detecting rodent presence. This is standard procedure for us and we perform thorough inspections for all types of pest control problems including for ats and mice. The interior inspection seeks to find any clues of rodent activity inside the premises as well of finding an interior entry-point. Just like the exterior inspection, the technician aims to find signs of active rodent presence. The technicians will look for bite marks, gnaw marks, scattered materials, gnawed wires, and rub marks left along the walls the rat passes.  Another important part of the interior inspection is that the technician will search in areas that rats are known to frequent. Rats are timid rodents that will take any measure possible to avoid detection.

Garages, attic spaces, and crawl spaces are a rat’s favorite spaces to nest and breed because of their infrequency at which they are visited compared to shared living spaces such as the living room and or rooms in the house. Garages give rats the perfect opportunity because of the clutter in these spaces. Rats can easily hide under the clutter and therefore avoid detection. Attics are the perfect space for rats to thrive and to breed because of the warmth, shelter, and protection it gives to keep the young and the mother safe. Rats can leave and enter as they please without any fear of being detected.

The technician found heavy activity inside the crawl space located at the basement level of the property and holes that lead into the crawl space well as rat droppings. However, no entry-points were found that lead into the living space. Rat droppings have a distinguishing shape that differs from mouse droppings. Rat droppings are longer in size and often black in color. The rat droppings are also distinguished by their pointy ends. Mice droppings on the other hand are small in size. They are said to resemble chocolate sprinkles and are the size of a grain of rice. It was suspected that the rats found their way from the dirt. Older houses that are in historic neighborhoods are more susceptible to intrusions due to structural damage created by the wear and tear of the building. Structural damage can double as entry-points for the rats. These entry-points consist of holes, cracks, crevices, and structural damage at the foundation of the home. People who are not familiar with the anatomy of rats are often surprised by how little space these rodents need to get inside of buildings. Apart from that, rats are great diggers. Notably, the Norway Rat is known for its burrows (rat holes) that it digs in the yards and lawns throughout Toronto.


Initial Measures Taken

In preparation for the eventual exclusion, exterior bait-stations were placed outside on the property. Exterior-bait stations are very important to lure the rats out from their nest. These bait-stations are tamper-proof containers that contain rodenticide in the form of bait blocks. The tamper-proof bait-box cannot be opened by pets and children and can only be opened by a key that the technician has at all times. This rodenticide is extremely irresistible. Once eaten the rats will perish. Inside snap-traps were placed as a precaution in case rats found their way on the interior of the premises. Snap-traps are very effective traps that will kill the rats in an instant when they come in touch with the snap trap. Placing snap-traps and bait-stations is done strategically by technicians based on where rats are most likely to pass. Placement of these traps and bait-stations is crucial to their eradication because it takes care of all the rats hidden and nestled inside the premises and rats that roam the exterior. It requires some patience on the customer end to see the results which are usually noticeable after 7 to 21 days.

After verifying the bait-stations sometime later, the technician noted that mild feeding has been taking place which points to a rat infestation. After verifying, the bait-stations are reloaded with the bait.

Exterior Rat Control Bait stations



It was proposed that 240 square feet were to be excluded on the interior of the dirt foundation located at the basement level of the house in the crawl space. The job was going to be invasive and required a lot of effort. Two technicians were working on installing the galvanized steel mesh. This material is resistant to all kinds of attacks by wildlife animals such as biting, gnawing, prying, pushing, and ripping. Moreover, galvanized steel mesh is flexible enough to cut to assume any shape needed to cover and secure a weak point on the entry-point. is durable enough to withstand the changing seasons and temperatures that Toronto goes through in the span of one year.

Rat Exclusion Services in Riverdale


In addition, a vapor barrier was to be installed along with the areas of concern.

vapor barrier


The technicians came back and verified the results of all the snap-traps and all the bait-stations. Once everything was checked out, the technicians move on to deodorizing and neutralizing any odor left by the rat carcasses. The smell left by these rat carcasses is described as rancid and rotten due to the rat’s high water content. During decomposition, the tissue breaks down which leads to a chemical reaction which in turn creates the offensive odor. The basement area became riddled with harmful bacteria and needed disinfection services using hospital-grade disinfectants.

Additional debris and allergens are taken care of using a HEPA Vacuum. The filter in the industry-grade vacuum allows trapping allergens that can make people sick.

The technicians went to work and installed the galvanized steel mesh to cover the dirt floor solidly held in place with washers and bolts with the help of a power drill. The reason why this was done is that the technicians on-site during the exterior and exterior inspection found no sign of an interior entry point. This led to believe that the rats must have found their way in by exploiting possible older pipes that lead to the home fed from the street. Older neighborhoods, notably located in Old Toronto still have remnants of older utility pipes running to houses situated on historic neighborhoods. By following these pipes, it must have led these rats to the basement level of the house where they eventually found their way to the crawl space. Since rats prefer solitude, it provided the rats the perfect space to thrive undisturbed. Finding the droppings, verified suspicions of rat activity in the crawl space.

The interior snap-traps were also verified and no report of any activity has been reported nor any breach of the vapor barrier.

Vapor barriers were installed along the areas of concern. This prevents moisture from building up inside the walls, floor, and ceiling which can lead to deterioration.


By installing vapor barriers moisture was kept out. By securing the dirt floor by installing and mounting galvanized steel mesh on the entire surface of the dirt floor, every opportunity or chance to access the crawl space was thwarted. By installing and strategically placing interior snap-traps as a precaution, it takes care of any rats that are on the inside of the premises. Placing exterior-bait stations loaded with bait that contain rodenticide, will lure all the rats out that are nestled inside the property looking for food outside and will kill all the rats roaming the property outside.

To take care of the aftermath that resulted in dozens or more rat carcasses, the crawl space was disinfected and vacuumed with a HEPA Vacuum that captures minuscule allergen particles. Rat infestations must be investigated when you hear activity in the walls or beneath your floor if you have a crawl space. The result can prevent extensive actions being taken and save lots of money in the end. Make sure you watch out for the signs of rat activity, especially when you have a house in Old Toronto. You can read more about our services here as well as specific case studies in Riverdale, Leslievielle and The Beaches.