Weep Vent Chewed by Rodent

Case Study: Mice Chew Through Weep Vent Covers in Toronto

The following case study details a mouse control service in Toronto, Ontario. Mice were removed from a multi-residential building with the help of bait stations and an exclusion of the exterior. Within a few weeks, the mice were gone. If you have been witnessing mouse activity in your home, give us a call. A technician will inspect your property and provide you with a lasting solution. Our services are guaranteed and come with a written warranty of up to 2 years.


House Mouse Entry Point

The homeowners in this case gave The Exterminators a call when they started spotting mice in their unit. Not sure what to do, they reached out to the professionals. Cases like these are common in Old Toronto. Mice come sneaking in through the holes they find in the walls and foundation of the home, then multiply, leaving feces in cabinets and dirtying the home. A technician came to inspect the next day.

The covid-19 pandemic was in full force at this time, and few people were vaccinated, so the homeowners in this case were concerned for their health. To ease their anxiety, the technician that came to their property wore an N-95 respirator, booties, and gloves. All our technicians comply with Ontario health guidelines and wear personal protective equipment to keep our customers safe.

Here, the technician found some mouse droppings in the kitchen. This is a typical sign of mouse activity. Droppings are small and dark, like black grains of rice. Mice leave droppings behind them, wherever they go, so they are a clear indication of where mice are most active throughout the house. To get rid of the pests, the technician recommended having some bait stations installed. Bait stations are little plastic boxes of rodenticide. Mice crawl inside them, feed on the rodenticide, then perish in their nests. Using professional baits like this is extremely effective.

Next, the technician looked for points of entry. Finding where the mice were coming from would give the owners the opportunity to stop any more mice from coming inside. What the technician found were plastic weep hole covers that mice had chewed through. Covering the weep vents was a good idea, but the material could be chewed very easily. The mice in this case chewed right through the covers and went into the house. To address this, the technician recommended having these covers replaced with ones made of stainless steel.

Weep Vent Chewed by Rodent
Rodents can chew through practically anything. And, while this hole might seem too small, it can fit a mouse. Mice can squeeze through any gap that would fit a ballpoint pen.

Treatment and Exclusion

The homeowners agreed to target the mice with bait stations inside the home, then to trap them indoors by replacing the weep hole covers. To help suppress the population outdoors, they also agreed to have one station outside. The technician got to work right away and placed 2 bait stations in the parts of the home where there was the most activity: in the kitchen and the living room. The mice would feed on the bait and perish within a few weeks.

Outside, the technician placed a bait station on the side of the home, near the weep vents where the mice were getting inside. Then, he took the plastic weep vent covers out and replaced them with ones made of stainless steel. These would let air flow and let the house expand and contract with the changes in season. Mice can chew through plastic, vinyl, wood, and soft metals, but these stainless steel covers are strong enough to resist them.

Stainless Steel Weep Vent Cover
These covers are flexible enough to let the wall expand, but strong enough to keep pests out.

A few weeks later, the technician returned to check on the bait stations. Mice had eaten the bait, and the homeowners reported that they were no longer witnessing any activity. To ensure that all the mice were gone, the technician refilled the stations. A few weeks after that, there were no signs of feeding. All the mice had been accounted for and blocked out for good.

Rodent Bait Station
The packets of rodenticide in this station were gone after a few weeks, indicating that mice were present and they were eating them.


When getting rid of mice, it’s important that you address the causes of the infestation. Find where the pests are coming from and keep them out with mouse-proof materials. Mice have surprisingly strong teeth. In this case, the mice had chewed through the homeowners’ plastic vent covers. If you have a mouse problem, get the help of The Exterminators and we will exclude your home. Our pest-proofing is guaranteed and comes with a 2-year warranty. Call us for pest control you can count on.