Trained Eye


Mouse Epidemic


I read your articles in the Winnipeg Free Press and I am hoping you can help.

We live in North Kildonan and our home backs onto Bunns Creek.  The area is beautiful but with the creek we have experienced a mouse epidemic in the last three years. We recently framed and insulated the inside of our basement and I am hoping that the finished walls will help with the problem.  However, one room in the back is still unfinished and I am concerned the mice will find their way back into my home, not to mention my daughter’s new bedroom in the basement.

How can we become pro-active and alleviate another year of mouse visitors?


The answer to your question is quite simple, but may be more difficult to implement than to discuss. Your question is timely, because this is the time of year when mice are beginning to look for warm sanctuaries from the coming cold months. You also have a little time left to implement my suggestions, before the snow flies, making changes difficult.

The answer to stopping mice or pest intrusion into your house is to cover or block any access points for entry. In simple terms, find the way or ways they are getting in and close them off. Also, you had better attempt to do this in the next couple of weeks, because it may be impossible to locate the openings under the snow. Unfortunately, mice do not have this restriction and travel easily underneath a heavy snow cover.

There are several common points of entry for the little rodents to most homes. These will normally be located near the ground, or even below grade. If your home has a full, deep foundation, the openings are often in the concrete walls, themselves. Check any protrusions from the foundation wall, such as electrical masts, gas piping, lawn faucet pipes, or exhaust vent hoods. If there are any gaps around these items, even as small as 5 or 6 mm, mice may be able to squeeze their way into your basement. Patching, caulking or blowing in foam insulation to these cavities, covered by a non-chewable covering such as concrete or pressure treated wood, will prevent entry.

Basement windows, especially if they have wood frames that may be partially rotten, are an excellent access point for Mickey and his friends. Check all your basement windows for gaps, and caulk or seal these small openings. If the sills, frames, or exterior brick mould is soft when probed with a screwdriver, it is time for repairs. If the damage is minor, the damaged wood may be removed and replaced with properly treated or painted wood. If the rot is more than a small portion of the wood, upgrading to a new vinyl window will seal the possible route of access and prevent further deterioration.

One of the most common points of entry for mice into homes is through corrugated, plastic dryer vents. The little pests can get into the ducting easily through the vent hood, which is normally located near the ground, and chew right through the thin plastic ducting. I have personally experienced this scenario and seen it in many homes, during inspections. You may not even know there is a hole in the vent, as it often so small that little moisture or heat will escape the ducting. If your dryer is vented in this manner, it should be replaced with solid metal ducting so damage to the ducting is not possible.

If your home does not have a full, deep foundation or if it has an addition, the source of the mouse intrusion may be through a crawlspace. Crawlspaces may be constructed with a concrete grade beam foundation or may be built on posts and pads with wooden skirting. In either situation, the grade beam or skirting may only extend a short distance below grade, and opening may occur from normal soil erosion around the addition. If the soil is simply eroded around the addition, you may be able to build it up with minor landscaping, enough to seal any small openings. Crawlspaces with dirt floors are probably the major source of mouse invasion into homes. If this is the case in your home, especially with the creek and green space nearby, you may need professional help. If the skirting is wooden and is damaged, it may have to be partially removed and replaced with pressure treated framing and plywood. If there are holes underneath a concrete footing or grade beam, further work may be needed.

In many cases the sudden presence of mice in the living space of a home can be very disturbing and messy, but a little careful check around the house may prevent this from happening. The nice thing about doing your own inspection and patching for mouse-proofing is that it will often save you a little money, in the long run. The suggested methods for sealing windows, doors and openings will also stop air leakage and may lower your heating bill.




P.O. Box 69021
#110-2025 Corydon Ave
Winnipeg, MB
R3P 2G9