Common Spring Pests in Southern Ontario & How to Prevent Them


As the last traces of winter fade, Southern Ontario residents welcome warmer temperatures with open arms. Unfortunately, spring brings not only blooming flowers but also a surge of pest activity. Insects and rodents shake off winter hibernation and invade our homes, gardens, and businesses in search of food, shelter, and breeding grounds. Understanding the most common spring pests and effective prevention strategies can help safeguard properties during this vulnerable season.

Most Common Spring Pests in Southern Ontario

Ants

Ants are among Southern Ontario’s most persistent spring invaders. They sneak through tiny cracks in search of sweet foods, water, and nesting sites. Once one ant discovers a food source, it leaves a pheromone trail attracting hundreds more. Carpenter ants can tunnel through wooden structures, while pavement ants target kitchens and pantries.

Cluster Flies

Cluster flies overwinter in wall cavities, attics, and basements and emerge in spring as temperatures rise. They often gather in large numbers around windows, seeking a way outdoors, and can be a nuisance especially in older homes.

Asian Lady Beetles

Similar to cluster flies, Asian lady beetles hibernate indoors and wake up with the first warm days of spring. These beetles are mostly harmless but can stain walls and create allergies when large numbers congregate.

Boxelder Bugs

Boxelder bugs, black-and-red insects, overwinter in protected cracks and crevices, particularly around boxelder trees. They can swarm sunny home exteriors and sometimes find their way inside.

Mosquitoes

Mosquitoes breed in standing water and begin emerging as soon as temperatures consistently stay above freezing. Their bites are more than a nuisance—they can spread diseases and disrupt outdoor activities.

Wasps

Queen wasps hibernate until spring and then start new nests, often under eaves or in attics. Active colonies can become aggressive if disturbed, posing a risk to family and pets.

Carpenter Bees

Carpenter bees drill round holes into wooden structures, decks, and sheds during spring, causing costly damage over time. Unlike honey bees, they don't live in colonies but can be territorial around their nesting sites.

Box Tree Moth

Box tree moth larvae feed voraciously on ornamental boxwood plants. Identification and prompt removal of infested clippings are crucial, as Ontario is part of the regulated area for this invasive species.

Beetles, Spiders, Centipedes, and Other Intruders

Spring also sees the awakening of beetles, spiders, centipedes, and millipedes from their winter hiding spots, all of which can make their way indoors and create problems, especially in damp areas.

Why Spring Pests Are So Active

Most spring pests in Southern Ontario survive winter by entering a dormant state in protected locations—homes, tree bark, leaf litter, or underground. Warmer temperatures trigger activity: insects emerge to feed, mate, and establish new colonies. Human structures provide shelter and easy access to food sources, making homes especially attractive to pests.

Top Prevention Strategies

Protecting property from spring pests requires a multi-layered approach combining professional help and homeowner vigilance. Here’s a strategic guide:

Seal Entry Points
  • Inspect and caulk cracks around windows, doors, and utility lines.
  • Repair ripped window or door screens.
  • Install door sweeps and mesh screens on vents and chimneys to block crawling and flying insects.
Reduce Moisture
  • Fix leaky pipes, faucets, and roof gutters.
  • Ensure proper drainage around your foundation.
  • Ventilate basements and crawl spaces to prevent humidity that attracts many types of insects.
Practice Good Housekeeping
  • Clean kitchens, dining areas, and pet feeding locations regularly.
  • Store food in airtight containers.
  • Dispose of trash promptly in sealed bins.
  • Sweep up crumbs and spills immediately.
Maintain Outdoor Spaces
  • Trim vegetation away from the foundation—shrubs touching the house give pests an entry bridge.
  • Remove leaf litter, mulch piles, and other debris that provide shelter for insects.
  • Store firewood away from walls and off the ground.
Eliminate Standing Water
  • Empty flowerpot trays, birdbaths, and tire swings.
  • Regularly clean gutters and downspouts.
  • Fill redundant ditches and holes where water can collect to prevent mosquito breeding.
Monitor for Early Signs
  • Look for trails of ants or droppings.
  • Check windowsills and attics for clusters of flies or lady beetles.
  • Inspect garden plants for chewed leaves or webs, which may signal caterpillar or moth infestations.

Professional Pest Control Services

A preventative pest control service in the fall and early spring is often the best way to control overwintering pests. Professionals use targeted treatments to stop infestations before they escalate, especially for pests that are difficult to eradicate with DIY methods. County living areas see recurring insect problems year after year, and ongoing pest management is recommended for peace of mind.

How Speedy Pest Control Can Help

At Speedy Pest Control, our experts specialize in eradicating Southern Ontario’s most persistent spring pests quickly and efficiently. We offer tailored pest management plans using the latest industry techniques, always with your family’s safety as our top priority. Our seasonal inspection service identifies vulnerabilities and treats current infestations while providing advice for long-term prevention.

Whether it’s ants, cluster flies, lady beetles, wasps, or invasive moths, our bonded and insured professionals deliver professional solutions for homes and businesses alike. Regular treatments, combined with property upkeep, ensure that spring pests don’t catch you off guard.

Spring in Southern Ontario is a pivotal time for pest prevention. Most infestations begin unnoticed—one trail of ants, a few overwintering insects, or some stagnant water can quickly escalate into a major issue. By taking proactive measures and investing in expert services, property owners can enjoy the beauty of spring without the nuisance of pests. If pest issues persist or preventive efforts seem overwhelming, contact Speedy Pest Control for a free consultation and keep your property pest-free all season long.