Pest Calendar: Seasonal Pests in Calgary
Calgary’s unique climate, with its cold winters, warm summers, and short transitional seasons, influences the types of pests that become active throughout the year. As a homeowner in Calgary, staying ahead of these pests can help you protect your home and family. Here's a detailed look at the pests active during each season in Calgary and what you should know about them.
Spring (March to May): Emergence of Overwintering Pests
As Calgary’s temperatures start to rise and the snow begins to melt, many pests awaken from their winter dormancy or emerge from indoor hiding places. Spring marks a time of renewal, but it also signals the start of pest activity.
Ants
- Pavement Ants: These small black or brown ants create colonies in cracks in sidewalks, driveways, and foundations. They forage for crumbs, sugary substances, and greasy foods, often invading kitchens and pantries. Colonies can grow to thousands of ants, and their persistent trails can be challenging to eliminate.
- Carpenter Ants: Larger than pavement ants, these black or dark brown ants hollow out wood to build nests, causing structural damage to homes. They are particularly drawn to damp or rotting wood, often around windows, door frames, and crawl spaces. Unlike termites, they don’t consume wood but can still cause significant harm over time.
Cluster Flies
Cluster flies spend winter hibernating in walls and attics. In spring, they emerge en masse, often gathering around windows or light sources as they look for an escape. While harmless to humans, their sudden appearance can be overwhelming. These flies are slightly larger than houseflies and move sluggishly, making them easier to swat but harder to prevent.
Boxelder Bugs
Recognizable by their black bodies with orange or red markings, boxelder bugs become active in spring after overwintering inside homes. They feed on boxelder trees, maple trees, and other plants but do not cause significant damage. Indoors, their presence is primarily a nuisance, as they cluster in large numbers on walls and ceilings.
Spiders
Most spiders become active in spring as they prey on other pests. Calgary is home to species like common house spiders and wolf spiders. While house spiders are small and harmless, wolf spiders are larger and more intimidating, though they pose no danger to humans. Spiders can be helpful in controlling insect populations but may alarm homeowners.
Summer (June to August): Reproduction and Peak Activity
Summer in Calgary is the height of pest activity, with many species taking advantage of the warm weather to breed and forage. Homes, gardens, and outdoor areas are particularly vulnerable to infestation. Outdoor activities are often disrupted by buzzing, biting, and stinging pests.
Mosquitoes
Mosquitoes are among the most annoying summer pests. Calgary’s proximity to wetlands, rivers, and areas with standing water provides ample breeding grounds. Only female mosquitoes bite, as they require blood to produce eggs. Their bites cause itchy, red welts, and they can transmit diseases such as West Nile virus. Mosquitoes are most active during dawn and dusk, especially after rain.
Wasps and Hornets
Wasps, including yellow jackets and paper wasps, build nests in eaves, sheds, trees, and underground burrows. Hornets, a larger and more aggressive species, often create aerial nests in high places like tree branches or roofs. These stinging insects become particularly defensive in late summer when their colonies reach peak size. Wasps and hornets are attracted to sugary foods and proteins, making outdoor meals a prime target.
Earwigs
Earwigs, with their menacing-looking pincers, are nocturnal pests that hide during the day under mulch, rocks, or garden debris. They feed on plants, decaying matter, and even other insects. While earwigs don’t bite humans, their pincers can pinch skin if handled. They’re often drawn indoors during wet or dry spells in search of shelter and moisture.
Grasshoppers
Dry summers in Calgary can lead to grasshopper outbreaks. These voracious herbivores chew through grass, flowers, and vegetable gardens, causing extensive damage. Certain species can grow up to 4 centimeters long, and their swarms can devastate crops and landscaping if left unchecked.
Fall (September to November): Seeking Shelter for Winter
As Calgary’s temperatures begin to cool, pests prepare for the winter. Many seek shelter indoors, looking for warm and secure places to overwinter, creating a surge in pest-related activity during the fall months. You may encounter a variety of pests in the fall in Calgary:
Rodents (Mice and Rats)
Rodents become highly active in seeking food and shelter. Mice and rats are notorious for their ability to squeeze through small gaps and reproduce rapidly once inside.
- House Mice: Small and agile, house mice can enter homes through holes as small as a dime. Once inside, they nest in walls, attics, and basements, gnawing on wires, insulation, and stored goods. Mice contaminate food and surfaces with their droppings, posing health risks.
- Norway Rats: Larger and more aggressive than mice, these rats burrow around foundations and invade basements or lower floors. Norway rats are capable of causing structural damage and are known carriers of diseases like hantavirus and salmonella.
Stink Bugs
Brown marmorated stink bugs become a noticeable nuisance in the fall. These pests seek warmth, often clustering on the sunny sides of homes before sneaking inside through gaps in windows, doors, or vents. When threatened or crushed, they release a pungent, unpleasant odor, making them particularly bothersome.
Spiders
In fall, spiders like wolf spiders, cellar spiders, and house spiders seek refuge indoors. Wolf spiders, although non-venomous, can be startling due to their large size and speed. Cellar spiders, often called “daddy longlegs,” are harmless and tend to settle in basements or garages.
Elm Seed Bugs
Unique to Calgary and surrounding regions, these small, reddish-brown insects swarm homes in large numbers during fall. They are primarily a nuisance pest, congregating around doors, windows, and vents. Elm seed bugs feed on elm seeds and are harmless but can create significant annoyance due to their numbers.
Winter (December to February): Quiet Survival Indoors
With Calgary’s freezing temperatures, outdoor pest activity ceases, but indoor pests thrive in warm environments.
Despite Calgary’s freezing temperatures, winter doesn’t mean a complete break from pests—many move indoors to escape the cold, continuing their activity within your home.
House Mice
House mice are a common winter invader. They build nests in warm, hidden areas like behind appliances or inside walls. Mice are prolific breeders, with one pair capable of producing dozens of offspring in a season. Their gnawing habits can damage electrical wiring, increasing the risk of fires.
Cockroaches
While not as widespread in Calgary as in warmer climates, German cockroaches can infest homes year-round. These resilient insects are often introduced through grocery bags, furniture, or boxes. They thrive in kitchens and bathrooms, feeding on crumbs, grease, and even glue. Cockroaches are notorious for spreading bacteria and allergens.
Bed Bugs
Bed bugs are adept hitchhikers, often introduced into homes through luggage, clothing, or used furniture. These nocturnal pests feed on blood and hide in mattresses, bed frames, and cracks. Their bites cause itchy welts, and infestations can spread quickly if not addressed.
Silverfish
Silverfish are small, wingless pests that thrive in Calgary’s heated, humid indoor environments. They feed on starchy materials like paper, books, and fabrics. These pests are often found in basements, bathrooms, and pantries, where they can persist undetected for long periods.
Why Pest Behavior Matters
Understanding pest behavior is critical for effective pest management. Seasonal habits like foraging, reproducing, and seeking shelter directly influence where pests are found and how they interact with your home.
Staying Ahead of Calgary’s Pests
Each season in Calgary brings unique pest challenges, from spring ants to winter mice. By understanding these seasonal patterns, homeowners can better anticipate issues and take appropriate action. Whether it’s outdoor pests disrupting summer barbecues or rodents invading your home during winter, staying informed is the first step in effective pest management.
For year-round pest control tailored to Calgary’s conditions, our professional services at Innovative Pest Solutions can provide peace of mind and protect your home from infestations. Our local pest control experts know Calgary’s unique challenges and can tailor solutions to your home. Contact us to learn more!