PestHelp Guide

Pest categories for Ontario

Browse detailed species profiles for rodents, insects, and spiders that commonly appear around Ontario homes, gardens, and property.

How to use this page

Each bubble below contains a short species description. Click the name for a full profile, including habitat, prevention, treatment, and when to call a pro.

Rodents

Rodents are structural pests that can chew wiring, insulation, and stored goods. Use the bubbles below to identify the type of rodent and open the right guide.

  • House Mouse

    Small gray mouse that often invades homes and eats stored food.

  • Norway Rat

    A large brown rat that burrows around foundations and sewers.

  • Deer Mouse

    A small brown-and-white mouse found in wild areas and homes in fall.

  • Meadow Vole

    A stocky field rodent that feeds on grass, roots, and seedlings.

  • Woodland Vole

    A forest-dwelling vole that lives under leaf litter and logs.

  • Southern Red-backed Vole

    A small woodland rodent with a reddish stripe on its back.

  • White-footed Mouse

    A slender mouse with distinctive white feet and a white belly.

  • Eastern Chipmunk

    A striped ground squirrel that stores seeds in burrows.

  • Eastern Gray Squirrel

    A large tree squirrel that often nests in attics and trees.

  • Fox Squirrel

    A large reddish squirrel that lives in open woods and suburbs.

  • Red Squirrel

    A small energetic squirrel that defends its seed caches.

  • Northern Flying Squirrel

    A nocturnal gliding rodent that lives in forest cavities.

  • Southern Flying Squirrel

    A small gliding squirrel common in southern Ontario forests.

  • American Beaver

    A large aquatic rodent that builds dams and lodges.

  • Muskrat

    A semiaquatic rodent with a flattened tail and marsh habitat.

  • Woodchuck

    A groundhog that digs burrows and eats gardens.

  • Porcupine

    A large rodent covered in sharp quills that chews wood.

  • Meadow Jumping Mouse

    A long-tailed, high-jumping meadow rodent.

  • Field Mouse

    A generic small mouse found in fields and structures.

  • Woodland Jumping Mouse

    A forest mouse with strong hind legs that hops through undergrowth.

Insects

Common Ontario insects range from nuisance ants and flies to damaging beetles and stinging wasps. Each bubble provides a quick description and link to a complete guide.

  • Carpenter Ant

    Large black or red ants that tunnel into moist wood and damage structures.

  • Pavement Ant

    Small brown ants that nest in sidewalk cracks and enter kitchens.

  • Odorous House Ant

    Tiny black ants that produce a rotten coconut scent when crushed.

  • Pharaoh Ant

    Tiny yellow ants that infest hospitals, apartments, and food service areas.

  • German Cockroach

    Small tan roaches commonly found in kitchens and bathrooms.

  • Oriental Cockroach

    Dark, slow-moving roaches that prefer damp basements and sewers.

  • American Cockroach

    Large reddish roaches that favor boilers, basements, and sewers.

  • Asian Longhorned Beetle

    A wood-boring beetle that attacks maples and hardwoods.

  • Emerald Ash Borer

    A bright green beetle that kills ash trees from the inside out.

  • Gypsy Moth

    A defoliating caterpillar that feeds on oak and hardwood leaves.

  • Japanese Beetle

    A shiny metallic beetle that eats flowers, fruits, and foliage.

  • Brown Marmorated Stink Bug

    A shield-shaped bug that invades homes in fall and emits an odor.

  • Boxelder Bug

    A black-and-red bug that clusters on warm walls and windows.

  • Asian Lady Beetle

    An orange spotted beetle that invades homes in fall.

  • Cluster Fly

    Slow indoor flies that overwinter in wall voids and attics.

  • House Fly

    Common indoor fly attracted to food and garbage.

  • Fruit Fly

    Tiny flies attracted to ripening fruit and fermenting liquids.

  • Drain Fly

    Fuzzy moth-like flies that breed in drains and sewage.

  • Mosquito

    Blood-feeding flies that breed in standing water.

  • Black Fly

    Small biting flies found near rivers and streams.

  • Deer Fly

    Biting flies with patterned wings that attack outdoors.

  • Bed Bug

    Small flat insects that hide in mattresses and feed on blood.

  • Flea

    Tiny jumping insects that feed on pets and people.

  • Carpenter Bee

    Large bees that bore smooth holes into untreated wood.

  • Paper Wasp

    Paper nests-building wasps that defend gardens and eaves.

  • Yellow Jacket

    Aggressive black-and-yellow wasps that nest underground.

  • Bald-faced Hornet

    Large white-and-black wasps with football-shaped paper nests.

  • Eastern Subterranean Termite

    Wood-destroying insects that feed in hidden galleries.

  • Spotted Lanternfly

    Invasive planthopper that damages trees and crops.

  • Clover Mite

    Tiny red mites that invade windows and walls in spring.

Spiders

Most spiders are harmless and help control insects, but some are pests or cause concern. Use these bubbles to find the species you saw.