Pests found in Toronto homes and businesses can be grouped into four practical categories: rodents, insects, birds and urban wildlife.

Each group behaves differently and creates different problems for a property.

Rodents such as mice and rats can enter buildings through structural openings and contaminate areas with droppings and urine. ‍

‍Insects include bed bugs, cockroaches, ants, wasps and other species with very different feeding, nesting and harbourage behaviours. ‍

‍Birds such as pigeons can create nesting and dropping problems around buildings. ‍

Urban wildlife, including raccoons and squirrels, can enter attics, roofs and other structural spaces.

Correctly identifying the type of pest and individual species is important because pest-control methods aren't interchangeable.

A treatment designed for cockroaches won't solve a bed bug problem. Mouse control requires a different strategy from squirrel exclusion. And an insect flying around your roofline isn't automatically a wasp.

This guide explains the four main pest categories, common examples found across Toronto and the Greater Toronto Area, and how to tell them apart.

What Is a Pest?

A pest is an organism considered unwanted because its presence or behaviour can affect people, property, food, animals, plants or the surrounding environment.

Whether an animal or insect is considered a pest often depends on where it is and what it is doing.

A raccoon moving through a Toronto ravine is wildlife.

A raccoon entering an attic and damaging the roof has become a wildlife-control problem.

An ant colony outside isn't automatically a household pest problem. Ants repeatedly entering a kitchen can be.

This distinction matters because professional pest management isn't about eliminating every insect or animal around a property.

It's about correctly identifying and managing organisms creating an actual problem.

What Are the 4 Main Types of Pests?

For practical structural pest identification, Guard More groups common Toronto pests into four broad categories:

These broad categories help narrow down a pest problem, but species-level identification is usually more useful when deciding what to do next.

For example, identifying something simply as an "ant" isn't always enough. Carpenter ants, pavement ants and pharaoh ants have different behaviours and can require different control strategies.

1. Rodents (Mice and Rats)

Toronto is often ranked as one of the "rattiest" cities in Canada. As the temperature drops in the fall, Norway rats and house mice seek the warmth of GTA basements and crawl spaces.

Rodents are mammals characterized partly by continuously growing front incisors adapted for gnawing.

For Toronto property owners, the two most important structural rodent pests are generally:

• House mice
• Norway rats

Both can exploit buildings for shelter, warmth, food and water, but they differ considerably in size and behaviour.

House Mice

House mice are small rodents that can exploit very small structural openings.

They may be found around:

• Kitchens
• Basements
• Wall voids
• Attics
• Garages
• Storage areas
• Utility spaces

Mice can nest in protected areas inside structures and travel between shelter and food sources.

How to Identify Mouse Activity

Common evidence can include:

• Small dark droppings
• Gnawed food packaging
• Shredded nesting material
• Scratching or movement inside walls
• Small gnaw marks
• Food disturbance

Seeing evidence in a kitchen doesn't necessarily mean the rodents entered the building through the kitchen.

A proper rodent inspection also considers the exterior structure and potential access points.

Norway Rats

Norway rats are substantially larger and heavier-bodied than house mice.

They are often associated with:

• Ground-level areas
• Basements
• Exterior burrows
• Waste-storage areas
• Garages
• Areas providing accessible food and water

Correctly distinguishing a rat from a mouse matters because the animals differ in behaviour, size, travel patterns and control requirements.

Mouse vs Rat

Signs of a Rodent Infestation

• Droppings: Small, dark pellets found in cupboards or along baseboards.

• Gnaw Marks: Holes in food packaging, drywall, or electrical wiring (a major fire hazard).
• Nighttime Noises: Scratching or scurrying sounds within walls or ceilings.
• Smudge Marks: Dark grease marks along walls where rodents frequently travel.

2. Insects (Cockroaches, Bed Bugs,Wasps, and Ants)

Bed bugs and cockroaches are more common in the GTA due to high-density living. In the summer, Carpenter ants are a major concern for those near wooded areas. Greater Toronto Area's wasp season peak during mid July to August with increased sightings of eastern yellow jacket wasps on/around trees, on/around property (soffits and roof lines), and around/under ground.

Insects are the broadest pest category on this list.

Common insect pests around Toronto properties include:

• Bed bugs
• Cockroaches
• Carpenter ants
• Pavement ants
• Pharaoh ants
• Odorous house ants
• Wasps
• Hornets
• Flies
• Beetles

Calling something an "insect problem" therefore tells you very little about how it should actually be controlled so identification needs to go further.

Bed Bugs

Bed bugs are small, flattened insects that feed on blood and are strongly associated with locations where people rest or sleep.

Common harbourage areas include:

• Mattress seams
• Box springs
• Bed frames
• Headboards
• Upholstered furniture
• Cracks and crevices near sleeping locations

Potential evidence includes:

• Live bed bugs
• Shed skins
• Eggs
• Dark fecal spotting
• Blood marks around bedding

Bites alone aren't sufficient to positively identify bed bugs because skin reactions can have many causes.

Cockroaches

Several cockroach species can occur in Ontario, but species identification matters.

Common examples include:

• German cockroaches
• American cockroaches
• Oriental cockroaches
• Brown-banded cockroaches

German cockroaches are particularly associated with indoor environments containing food, warmth and moisture.

Common locations can include:

• Kitchens
• Bathrooms
• Under sinks
• Behind refrigerators
• Behind stoves
• Cabinets
• Plumbing areas
• Cracks and structural voids

Potential evidence includes live cockroaches, droppings, egg cases and shed skins.

Ants

Not all ants entering Toronto properties are the same.

Guard More treats species including:

• Carpenter ants
• Pavement ants
• Odorous house ants
• Pharaoh ants

Species identification is particularly important here.

Carpenter Ants

Carpenter ants excavate galleries in wood for nesting rather than eating the wood itself.

Their presence can be associated with damp or moisture-affected wood.

Pavement Ants

Pavement ants commonly establish colonies around soil, foundations, concrete and pavement and may forage inside buildings.

Pharaoh Ants

Pharaoh ants are small indoor ants whose colony behaviour makes correct treatment particularly important.

Wasps and Hornets

Wasps are another group where correct identification affects the response.

Common structural pest problems can involve:

• Yellowjackets
• Paper wasps
• Bald-faced hornets
• European hornets

Depending on the species, nests can be found:

• Under eaves
• Around soffits
• Inside wall voids
• In attics
• In trees or shrubs
• Underground

Don't assume every yellow-and-black flying insect is the same species—or even a wasp.

Bees, wasps and other flying insects perform different ecological roles and shouldn't automatically receive the same response.

Signs of an Insect Infestation

• Sightings: Seeing more than one or two insects usually indicates a colony is nearby.
• Shed Skins: Cockroaches and bed bugs leave behind translucent "shells" as they grow.

Video: Severe Bed Bug Infestation on Futon Couch

Video: Carpenter Ant infested rotted wood

3. Birds (Pigeons and Starlings)

In urban areas like the Downtown core or Etobicoke, pigeons are the primary concern. Their acidic droppings can erode building materials and transit infrastructure. Birds and bird nests commonly spread red bird mites which are very hard to get rid of. In our experience, bird nests that are built inside of dryer vents can quickly spread the throughout a living space.

Most birds are simply part of Toronto's urban ecosystem and require no control.

Problems arise when certain species repeatedly nest, roost or congregate around buildings in ways that cause property, sanitation or operational problems.

One of the most recognizable examples is the pigeon.

Pigeons

Pigeons are extremely well adapted to urban environments.

Buildings provide artificial equivalents of the ledges and protected spaces birds would otherwise use for resting or nesting.

Potential problem areas include:

• Balconies
• Roof ledges
• Window ledges
• Building entrances
• Signage
• HVAC areas
• Parking structures
• Commercial loading areas

The problem is generally not the existence of pigeons in Toronto.

It's persistent roosting or nesting in locations where accumulated droppings, nesting material or obstruction creates a property-management issue.

Evidence of Bird Activity Around a Building

Look for:

• Concentrated droppings
• Feathers
• Nesting material
• Repeated roosting
• Birds consistently entering structural openings
• Debris around vents or roof areas

Signs of a Bird Infestation

• Concentrated Droppings: On balconies, window sills, or cars.
• Debris: Nesting materials (twigs and straw) blocking your gutters or HVAC vents.

Are All Birds Pests?

No.

Calling birds a pest category doesn't mean every bird on a property should be controlled.

The species, location, behaviour and applicable wildlife protections matter.

If a bird is simply visiting a garden or sitting in a tree, you probably don't have a pest-control problem.

Structural nesting, repeated roosting or birds entering a building are different scenarios.

Correct species identification should come before deciding whether intervention is appropriate.

4. Urban Wildlife (Raccoons, Skunks, and Squirrels)

Toronto is famously the "Raccoon Capital of the World". Our local wildlife is highly intelligent and has adapted perfectly to urban life.

Toronto and the surrounding GTA contain substantial urban wildlife populations.

Animals commonly associated with property problems include:

• Raccoons
• Squirrels
• Skunks

Again, these animals aren't inherently pests.

A squirrel in a tree is wildlife.

A squirrel chewing through a roof vent and nesting in an attic has become a structural wildlife problem.

Raccoons

Raccoons are highly adaptable and comfortable living alongside people.

Properties can provide them with:

• Food
• Garbage
• Shelter
• Attic space
• Decks
• Roof access
• Protected denning locations

For homeowners, the bigger issue occurs when a raccoon gains access to the structure.

Potential signs include:

• Roof damage
• Damaged vents
• Torn soffits
• Heavy movement in an attic
• Droppings
• Disturbed insulation
• Repeated activity around the same roof area

Wildlife control needs to consider both the animal and the structural opening it is using.

Simply getting an animal outside doesn't prevent it from accessing the same opening later.

Squirrels

Squirrels can create structural problems when they access:

• Attics
• Rooflines
• Soffits
• Vents
• Wall cavities

Their gnawing behaviour can enlarge openings and damage building materials.

Activity is often associated with scratching, running or chattering sounds around attic and roof areas.

As with raccoons, effective wildlife work should consider removal and exclusion.

Skunks

Skunks are more likely to create problems around the exterior of a property than inside an attic.

They may shelter underneath:

• Decks
• Porches
• Sheds
• Other accessible structures

They can also dig in lawns while searching for food.

If an animal is living underneath a structure, correct identification matters before attempting exclusion or other control.

Signs of an Wildlife Infestation

• Structural Damage: Torn roof shingles or chewed soffits (common for squirrels).
• Garden Havoc: Overturned bins (garbage is most common for a food source) or dug-up lawns (often raccoons or skunks).
• Vocalizations: Heavy thumping or "chattering" within walls or the attic space.

If wildlife has been living in the attic for months, the attic may be contaminated with wildlife urine and feces. There are potential health risks to humans entering the contaminated space like roundworms from raccoons. From studying 1,539 raccoons, researchers found 35% of raccoon had roundworms. Roundworms can cause fever, abdominal pain, and diarrhea.

Insects vs Rodents vs Wildlife: What's the Difference?

The biggest distinction isn't simply appearance.

The pest category influences how the problem needs to be investigated and managed.

Insect Pest Control

Often involves identifying:

• Species
• Harbourage
• Food/moisture sources
• Colony or nesting behaviour

Control can include species-specific baiting, residual treatment, physical treatment or exclusion.

Rodent Control

Requires consideration of:

• Species
• Travel routes
• Food sources
• Nesting
• Structural entry points

Control may combine trapping or baiting with exclusion.

Wildlife Control

Usually focuses heavily on:

• Species
• Structural entry
• Denning/nesting
• Humane removal
• Exclusion
• Property repair/protection

Bird Control

Focuses on species identification, roosting/nesting behaviour and the particular building conditions creating the conflict.

That's why pest identification comes before pest treatment.

What Type of Pest Is in My House?

If you're trying to identify an unknown pest, start with evidence rather than guessing.

Ask these questions when coming across a pest:

What does it look like?

Note its:

• Approximate size
• Colour
• Body shape
• Wings
• Number of legs
• Distinctive markings

Where did you find it?

Location can narrow down identification.

Was it:

• In a bed?
• Under the kitchen sink?
• Behind an appliance?
• In the basement?
• Inside an attic?
• Around the roof?
• Outside?

When is it active?

Some pests are more active at night, while others are regularly seen during daylight.

What evidence has it left?

Look for:

• Droppings
• Gnawing
• Shed skins
• Eggs
• Nesting material
• Wood debris
• Structural damage
• Tracks or smudge marks

Take clear photographs where possible.

A good image of the actual pest can be considerably more useful for identification than a description such as "small brown bug."

Common Types of Household Pests in Toronto

For Toronto and GTA homeowners, some of the most relevant household and structural pests include:

Why Pest Identification Matters

Correct identification determines what happens next.

Misidentifying a pest can result in:

• Treating the wrong areas
• Using an inappropriate control method
• Missing structural entry points
• Failing to locate harbourage
• Unnecessarily treating harmless insects
• Allowing the actual problem to continue

For example:

A bed bug requires a completely different inspection and treatment strategy from a German cockroach.

A mouse inside a wall requires a different approach from a squirrel inside an attic.

And a raccoon on your lawn doesn't automatically require wildlife removal, while a raccoon entering through a damaged roof does.

Identification isn't just knowing the name of the animal.

It's understanding what species is present, where it is and why its behaviour is creating a problem.

Frequently Asked Questions About Types of Pests

What are the four main types of pests?

Guard More groups common structural pests into four practical categories: rodents, insects, birds and urban wildlife. Each category contains individual species requiring more specific identification.

What are common household pests?

Common household pests in Toronto include mice, rats, bed bugs, cockroaches, ants and wasps. Raccoons and squirrels can also become structural pest problems when they enter homes.

What are examples of rodent pests?

House mice and Norway rats are two important structural rodent pests found around Toronto properties.

What are examples of insect pests?

Common insect pests include bed bugs, cockroaches, carpenter ants, pavement ants, pharaoh ants, wasps and hornets.

What wildlife can cause problems around Toronto homes?

Raccoons, squirrels and skunks can create property problems when they den, nest, forage or gain access to structures.

Are all insects considered pests?

No. An insect is generally considered a pest in this context because its presence or behaviour is creating an unwanted problem. Many insects are harmless or beneficial.

Are raccoons and squirrels always pests?

No. Raccoons and squirrels are normal parts of Ontario's wildlife. They become a property-management concern when their behaviour creates problems such as structural entry, denning or damage.

How can I identify an unknown pest?

Photograph the pest and record where it was found, its approximate size, colour, behaviour and any associated evidence such as droppings, shed skins, nesting material or property damage.

Found a Pest You Can't Identify?

Correct identification is the first step towards deciding whether control is actually required.

If you've found an insect, rodent or wildlife activity around your property, take clear photographs of the pest and any evidence you've discovered.

Guard More Pest Control provides professional pest identification and pest-control services across Toronto and the Greater Toronto Area.

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About Guard More Pest Control

Guard More Pest Control provides professional pest control and wildlife removal services for residential and commercial properties across Toronto and the Greater Toronto Area.

Guard More's current services cover insects, rodents and wildlife including bed bugs, cockroaches, mice, rats, ants, wasps, raccoons and squirrels.