How to Identify a Rat Problem In Your Home

The sooner you can identify a rat problem, the sooner you can get rid of them in your home.

The Types of Rats That Can Be Found In Canada

Of the rodents commonly found in Canada, rats are the largest sized rodents with adult males reaching up to 48cm (19 inches) long when measuring from nose-to-tail. Rats can weigh up to 453.592g (1lb) and consume just about anything in sight which explains how they could find interest in occupying the interior and exterior of your home.

Norway Rats

This species of rat originated in Norway before immigrating to Canada by way of England. Having lasted for centuries, Norway Rats have developed into rodents that can resiliently find their way to sources of food and water, which can also mean the food and water in your home.

These rats have a bulkier body than Roof Rats and can reach up to 40cm (16 inches) in length. Unlike Roof Rats, Norway Rats have more of an interest in staying low to the ground and have an affinity for chewing cables, baseboards and holes in walls while in pursuit for food and water. Norway Rats scavenge through garbage and sewers and are known to bring hazardous oils and other residues into your home that can drastically alter your quality of living.

With steady access to food, water and shelter, Norway Rats can live up to 18 months with a gestation period of 23 days. Female rats of this species can birth up to 12 babies at a time which is a testament to how quickly rat colonies can develop when at full health. In order to thrive, Norway Rats will set up their nest as far as 100 ft away from a source of food and water to maintain their colony.

norway rat

Roof Rats

As its name suggests, Roof Rats have the capability to climb into higher areas of your home that other species of rodents do not typically favour. These rats can be found burrowed in attics and are known to have tails that are longer than their bodies. This species of rat has fur that is darker than Norway Rats with a more slender body.

Despite its unique ability to climb like no other rodent, Roof Rats look for similar opportunities to enter your home and scout the same types of food and water sources as Norway Rats do. When at full health, Roof Rats can live up to 18 months and birth up to 8 babies in the span of 22 days. To feed their colony, Roof Rats can set up a nest as far as 91m (300 ft) from what they’ve identified as a main source of food and water.

roof rat


Commonly found in western parts of North America and named after living in wooded forest areas, Woodrats have been found in arctic parts of Canada despite also being known to live and survive in the desert regions of the United States. With a grayish-brown fur, Woodrats are the most fluffy of rats and use their coat to withstand harsh conditions of the arctic.

With the ability to grow up to 18 inches in total length, Woodrats vary in size based on their location. These nocturnal rats spend the majority of their life outdoors in forestry and are vegetarian by nature. Seeds, nuts, berries and leaves are all these woodrats need to survive the arctic and deserts that they scavenge.

Marsh Rice Rats

Named after the conditions that these rats choose to live in, Marsh Mice Rats are rarely found in Canada despite being seen as close as New Jersey, NY in the U.S. These rats are semi-aquatic and choose the wetlands to live where they consume vegetation, fungus and marsh grass. Despite not being known to frequent homes the way that other species of rats do, Marsh Rice Rats are known to burrow and nest in drier environments like houses nearby to bodies of water.

Marsh rats

Common Habits and Characteristics of Rats

How Rats Enter The Home

Rats only need a hole the size of a Canadian quarter in order to enter your home. Small cracks and soft areas of your drywall is all it takes for rats to begin to create a hole that they can use to enter your home. With its heightened sense of smell, rats can navigate their way from the smallest crack in the corner of your home’s exterior, to the food in your kitchen quite easily. The following areas are some of the most common ways that rats enter your home from the roof, or from the ground:

  • Pipes
  • Air Vents
  • Overgrown shrubbery and trees
  • Drains
  • Doors
  • Exterior gaps in the home due to construction
  • Uncapped chimneys

Favourite Food Types

Rats only require approximately 1 oz of food to thrive as these rodents have no preference of food and source of water. With a high metabolism and large appetite, these rodents can eat up to ⅓ of their body weight each day. Their appetite is a direct relation to the amount of droppings that may be seen in your home when you begin to suspect that rats exist in your living space.

Rats are considered omnivores and have a long list of favourite things to consume despite eating just about anything:

  • Berries, seeds, and nuts that fall from trees and bushes
  • Birdseed
  • Candy
  • Compost
  • Dry goods and bulk foods
  • Farm field corn, wheat, and beans
  • Feces
  • Frozen food
  • Fur
  • Garbage
  • Garden vegetables
  • Grass seed
  • Leather
  • Meat, poultry, and fish
  • Milk
  • Other rodents
  • Pet food and chicken feed
  • Soap
  • Spoiled food
  • Squirrel food


With one rat species preferring higher ground more so than the other, habits when it comes to burrowing a nest differs between Roof Rats and Norway Rats. Aside from nesting in your home, this is the difference in burrowing between the two types of rats:

  • Attics, roofs and in trees are preferred destinations for these rats to nest. During hotter seasons like in the middle of the summer, Roof Rats are also known to create nests in areas beneath concrete slabs and in between tree roots.   
  • There are many more options for Norway Rats to burrow due to their preference on the ground. These rats dig holes more than 1 ft into the ground and can create enough space for multiple rats to live together while also storing food at the same time.

Signs of Rats In Your Home

The one thing that all signs of rats in your home have in common is that they all lead to poor living conditions for you, your family and your pet animals. Rats are not only a nuisance when it comes to maintaining a clean home and maintaining your food, but rats can bring toxic pathogens into your home that will greatly affect your quality of life very quickly. As soon as any of these signs are seen in your home, it is important to control the issue immediately:

woman looking in cupboard

Chewed Holes

In order for rats to enter your home, holes the size of a Canadian quarter in your drywall are sure signs that rats have entered your home. Rats will chew at just about everything in your home to identify a spot that will give enough for them to create an entryway.

Grease Marks

Oily rub marks from the residue found in rat fur is a significant sign of rats in your home. As rats explore your home, they typically take the same paths everytime which over time, creates trails of oil that they leave behind as they frequent your living space.

Bite Marks

As rats explore your home in pursuit of food and water, bite marks in your baseboards and cables are sure signs that rats are in your home. Bite marks can be found anywhere that rats are as they bite anything for the sake of identifying food and also points of entry to eventually chew through to other areas of your home.


Nests can be created by rats just about anywhere that is typically left in the dark and rarely occupied by humans and pet animals. Attics, cupboards, closets and garbage cans are all places that rats choose to nest.

Sounds & Activity

As nocturnal creatures, these rodents are more likely to be heard in the middle of the night when the least amount of activity occurs. Scratching and squeaking can be heard inside of walls as rats begin to scavenge for food.

Changes In Pet Behaviour

Pets such as dogs and cats that have become more attentive to walls and other places in your home that are usually of no interest to them are likely detecting rodents in your home. Paying close attention to pet behaviour can lead to the discovery of a rat problem in your home.

The Significance of Droppings and Urine Ordour

Droppings between the two rat species are distinctly different with Norway Rat feces being larger and more oval shaped than droppings from Roof Rats. Rat droppings in general are dark brown and range between ½ to ¾ inches in length. Rat droppings are significantly larger than mice droppings although all types of droppings should be treated the same and with the utmost caution. With rats defecating 40 to 50 times per day on average, droppings are likely to be seen anywhere in your home that they are most active. With droppings also comes urine which has a toxic smell that contains pathogens that can drastically change the air quality in your home for the worse.

The longer you leave droppings unattended, the more it is likely to increase in amount in your home which can lead to an infestation of rats over time.


Signs Of An Infestation

An abundance of rats in your home will always mean more droppings, more unusual activity from your pets and many of the other signs of rats in your living area. One of the largest and more concerning issues at the start of an infestation is when you begin to physically see rats and identify rodent activity in the daytime. Despite rats being nocturnal, a large amount of rats in your home can mean activity throughout the day and not only at night.

At this point, drastic measures need to be taken as you begin to control the rat infestation in your home.

How Rats Can Damage Your Home

Especially during an infestation, rats can create multiple holes in your drywall to find the best path to sources of food and water in your home. Rats will stop at nothing in their pursuit of food in your home which also involves chewing and gnawing at just about anything that may taste like food, but also may be an easy opportunity to create a hole to find their way deeper into your living space. Wooden foundations of homes, exposed electrical wiring, packaged food and the destruction of important boxes and paper documents in your home are all susceptible to rats in your home.