Transparent Sealant Along Soffit Edge

Case Study: Mice Enter Basement, Climb Into Attic in Markham

The following case study deals with a mouse removal service in Markham, Ontario. Mice were infesting the basement of a single-family home, then, following treatment, moved into the attic. A complete pest-proofing of the premises, along with a thorough bait program eliminated the mice on this property and has kept this property pest-free. For more information on mouse control in Markham, give us a call.


The owners of this Markham property reached out to Mouse Control in December after spending a few weeks trying to rid themselves of an infestation in their basement. They were catching mice on a regular basis but could not get rid of the problem entirely. Problems like these are common in single-family homes when the weather is cold outside. A technician quickly arrived on the scene to investigate.

With every pest problem, our technicians complete a thorough inspection of the home’s exterior and interior. This identifies potential points of entry, and it determines the severity of the infestation. Having a proper understanding of the situation allows us to solve the problem more effectively.

In this case, the technician found a wall vent that was left exposed on the sides of the house. Wall vents can, unfortunately, be chewed through by rodents. Mice are also small enough to slip through their openings and make their way into the house. The weep vents on this property were also wide enough to fit a mouse. Both of these vent types could be protected with mesh, which would keep mice and other rodents out for good.

Wall Vent Mouse Entry Point
Rodents can chew through practically anything, including hard plastic and aluminum.

Following the exterior inspection, the technician went into the basement to take a look. The homeowners had spotted mice running along the walls of the basement, and they had caught a few in some snap traps from the hardware store. The technician recommended having the vents covered outside and having a baiting program set up in the basement to rid the home of mice.

Treatment and Exclusion

Immediately after the inspection, the technician installed 16 weep vent covers and one piece of mesh over the wall vent. The mesh covering the wall vent consisted of a quart-inch, 16-gauge, galvanized steel mesh. The thickness of the mesh prevents rodents from chewing through, and its outer coating of zinc makes it weather-proof. Similarly, the weep vent covers would keep mice out while preserving airflow.

Weep Vent Covers
Weep vent covers are discreet and effective. They continue to let air flow through the wall, preventing moisture buildup while keeping pests out.

The technician then placed a few bait stations in areas of mouse activity. These stations consist of little plastic boxes that contain a potent rodenticide. Mice would enter the boxes, feed on the bait, then perish in their nests. Bait stations are extremely effective against rodents. They are tamper-proof and require a key to open, so they are safe for household use. Only a licensed technician has access to these stations.

Bait Station Basement
Bait stations work best when they are placed along the walls of the home, where mice prefer to walk. Mice are nearly blind, and follow the same paths every day.


A month later, in January, the technician returned to check up on the bait stations. Checking their interior would determine at what rate the mice are feeding. Some feeding was reported, with the most happening under the kitchen sink. The stations were then refilled to continue the treatment.

All was well for a few months, when the homeowners started to see the signs of a mouse problem once again. They could hear scratching in the attic and spotted some mice in the house. Because we provide warranties on our work, a technician quickly returned to check things out.

This time, the technician noticed a gap between the soffits of the home and its outer brick wall. While it is less likely for mice to use this entrance than an opened air vent, it is possible when there is no other way in. A complete proofing of this gap was recommended to keep mice out.

Soffit Gap Mouse Entry Point
A larger gap, like this one, will fit squirrels and young raccoons. An adult raccoon may even grasp the edges of the gap and tear it open.
Burrow hole in Insulation
Burrow holes were found within the insulation of the attic, proving that mice were getting inside.
Bait station in Attic Insulation
A bait program was set up inside the attic to target the mice there.

Following the second inspection, a total of 137 feet was sealed off. To do so, the technician installed a mesh along with the gaps, then sealed them in with caulking. This would keep mice, squirrels, and other animals from using these openings to get inside the attic.

Mesh Along Soffit Edge

First, a mesh is wedged into the gap to ensure that no rodents can chew through.

Transparent Sealant Along Soffit Edge
Then, a transparent caulking is applied to hide the mesh and keep everything out. This type of exclusion works incredibly well against small pests like mice, bats, and wasps.


Within a few weeks, the mice in this case were gone. The complete pest-proofing of the home’s exterior, along with the consistent baiting of the interior got rid of the mice indoors.

Mice are persistent pests that can climb their way up the sides of the house to get inside. They can also be very difficult to get rid of without professional help because they breed too quickly to keep up. If there are mice in your home, give us a call and a technician will come to inspect. We provide lasting, guaranteed solutions to all mice problem.

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