Our Illinois Pest Calendar: A Seasonal Guide

Keeping your home pest-free in Illinois requires year-round vigilance. Each season brings its own challenges as different pests become active. Understanding the seasonal pest cycle can help you take proactive steps to prevent infestations. Here’s a comprehensive breakdown of what to expect and how to prepare.

Spring (March - May): Pests Wake Up

As temperatures rise and daylight hours increase, many pests emerge from their winter hiding spots, looking for food and water. This is also the time when many insects begin their breeding cycles, which can lead to rapid infestations if not managed early.

Common Spring Pests

• Ants – Carpenter ants and pavement ants become active and start foraging for food, often invading kitchens and pantries. They may also begin nesting in moist wood or structural voids, leading to potential damage.
• Termites – Spring is peak swarming season for termites looking to establish new colonies, making it crucial to watch for discarded wings and mud tubes around your home.
• Mosquitoes – As standing water from spring rains accumulates, mosquito populations begin to grow, increasing the risk of bites and mosquito-borne diseases.
• Ticks – With wildlife and pets becoming more active outdoors, ticks start latching onto hosts, potentially spreading diseases such as Lyme disease and Rocky Mountain spotted fever.
• Spiders – House spiders and wolf spiders may become more visible indoors as they search for prey, particularly in basements, garages, and storage areas.

Spring Pest Prevention Tips

• Inspect your home’s foundation for cracks and seal entry points to prevent ants and termites from gaining access.
• Clear yard debris, trim trees, and eliminate wood-to-soil contact to reduce termite risk.
• Repair leaks and eliminate standing water to prevent mosquito breeding, especially in clogged gutters and low-lying areas of your yard.
• Start pest control treatments early to prevent major infestations and monitor for signs of increased activity.

Summer (June - August): Peak Pest Activity

Warm weather brings an explosion of pest activity as insects and rodents take advantage of long days and abundant food sources. Many pests are at their peak reproductive stages, meaning infestations can escalate quickly if not properly managed.

Common Summer Pests

• Mosquitoes – Hot, humid conditions accelerate breeding, making outdoor spaces uncomfortable and increasing the risk of diseases like West Nile virus.
• Wasps & Hornets – Paper wasps, yellowjackets, and hornets aggressively build nests in eaves, trees, and even inside wall voids. Their stings can be dangerous, especially for those with allergies.
• Fleas & Ticks – Summer is peak season for these biting pests, especially in homes with pets that spend time outdoors. Infestations can quickly spread throughout the home if untreated.
• Cockroaches – Increased humidity attracts roaches to kitchens, basements, and drains, where they can quickly multiply and contaminate food sources.
• Fruit Flies – Overripe produce, fermenting liquids, and garbage bins create the perfect breeding ground for fruit flies, leading to annoying and persistent infestations.

Summer Pest Prevention Tips

• Use insect repellent and keep grass trimmed to reduce tick populations and minimize flea exposure for pets.
• Inspect outdoor play areas and home exteriors for wasp nests and remove them safely before they become a bigger problem.
• Store food properly, keep garbage sealed, and clean up spills immediately to deter cockroaches and fruit flies.
• Empty birdbaths, drain standing water, and install mosquito-repelling plants to keep mosquitoes at bay.

Fall (September - November): Pests Seek Shelter

As temperatures drop, many pests begin moving indoors in search of warmth, food, and safe harborage for overwintering. This is a critical time for sealing your home against invaders.

Common Fall Pests

• Rodents (Mice & Rats) – Cooler weather drives rodents inside, where they nest in walls, attics, and basements, potentially causing damage by gnawing on wiring and insulation.
• Boxelder Bugs – These red-and-black bugs seek warmth on sunny exterior walls and sometimes enter homes in large numbers, becoming a nuisance.
• Stink Bugs – Another overwintering pest, stink bugs gather on windows and doors before sneaking inside, releasing a foul odor when disturbed.
• Spiders – Some species, like house spiders, become more noticeable indoors as they hunt for insects hiding in dark corners.
• Cockroaches – As food sources become scarcer outdoors, roaches move inside, seeking warmth and moisture in kitchens and bathrooms.

Fall Pest Prevention Tips

• Seal cracks around doors, windows, and foundations with caulk or weather stripping to block entry points for pests.
• Store firewood at least 20 feet away from the house to reduce rodent harborage and discourage overwintering insects.
• Use dehumidifiers in basements and crawl spaces to deter cockroaches and silverfish from settling in.
• Inspect and replace damaged weather stripping and door sweeps to prevent pests from sneaking inside.

Winter (December - February): Indoor Invaders

While outdoor pest activity slows significantly, many insects and rodents shift their focus to indoor survival. Homeowners must remain vigilant against pests seeking warmth and food.

Common Winter Pests

• Rodents – Mice and rats are the top winter pests, often nesting in insulation, storage areas, and pantries, contaminating food and spreading diseases.
• Silverfish – These moisture-loving insects thrive in basements, bathrooms, and laundry rooms, feeding on paper, fabric, and glue.
• Bed Bugs – Increased travel and holiday gatherings can spread infestations, as these hitchhiking pests move between luggage, clothing, and furniture.
• Cockroaches – Still active in heated homes, roaches hide in cracks and crevices, especially near food sources and warm, humid areas.

Winter Pest Prevention Tips

• Set traps and monitor for rodent activity in garages, attics, and basements, sealing any potential entry points.
• Reduce clutter and vacuum regularly to eliminate hiding places for silverfish, bed bugs, and cockroaches.
• Be cautious when bringing in holiday decorations or secondhand furniture, as these can harbor hidden pests.
• Maintain a clean home, especially in food storage areas, to minimize pest attraction.

Year-Round Pest Prevention

While some pests are more active during specific seasons, a proactive approach can keep infestations at bay all year long. Scheduling routine pest inspections, keeping food sealed, maintaining your yard, and eliminating excess moisture are all crucial steps. Working with a professional pest control service ensures long-term protection and peace of mind.

By staying ahead of seasonal pest threats, Illinois homeowners can enjoy a more comfortable and pest-free home year-round. If you suspect a pest issue, don’t wait—early intervention is key to preventing costly infestations!

For more information or to schedule your pest inspection or treatment, contact our exterminators at Garella Pest Services. Backed by over 80 years of experience, our local and family-owned pest control company is here to help keep your home pest-free year-round!