Canadian Seasonal Pest Calendar

What’s Bugging Homes and Businesses from Fall Through Winter

From the first cool nights of September to the deep freeze of February, Alberta homes go through a predictable pest cycle. Use this homeowner‑friendly calendar to know what to watch for and when to call for help.

September–October: Fall Invaders Move In

As evenings cool, “fall invaders” start looking for a cozy place to spend the winter. These include:

• Cluster flies gathering on sunny exterior walls and sneaking into attics and spare rooms.
• Wasps searching for protected spots in soffits, wall voids and sheds.
• Beetles and other overwintering insects slipping in around windows, siding and rooflines.

What to do:

• Walk the exterior and seal gaps around windows, doors, vents and utility lines.
• Repair screens, add door sweeps and caulking, and store firewood away from the house.
• Schedule a fall exterior inspection before the first hard frost.

November–February: Mice Become the Main Problem

Once temperatures drop, mice become the top winter pest for Alberta homeowners. They move into:

• Basements, crawlspaces and attached garages.
• Kitchen cabinets, pantries and under appliances.
• Attics and wall voids, using plumbing and wiring runs like highways.

Signs include droppings, scratching sounds, gnaw marks and shredded nesting materials.
What to do:

• Seal foundation cracks and gaps around doors and garage doors.
• Store food (including pet food and bird seed) in sealed containers.
• Have monitoring and exclusion set up in late fall before activity peaks.

December–February: Indoor “Hitchhikers”

Heated homes stay active for other pests all winter:

• Bed bugs brought home after holiday travel.
• Pantry pests in flour, cereals, nuts and baking supplies.
• Occasional cockroaches in multi‑unit buildings or older homes with shared walls and plumbing.

What to do:

• After trips, inspect mattresses and headboards, unpack directly into the washer, and dry on high heat.
• Check dry goods for webbing, beetles or moths; discard anything suspicious.
• Act quickly on any bites, bugs or droppings rather than waiting to “see if it goes away.”

Using this fall‑through‑winter guide, you can time inspections and prevention work before pest pressure peaks—keeping your home more comfortable, cleaner and easier to protect year‑round.