Insects and pests

Animals are all useful in their own way: to other species, to the environment, to the food chain, etc. Spiders and praying mantis, for example, eat huge quantities of insects, which helps keep down populations. Birds feed on seeds and fruits that they spread in the forest. Squirrels and rodents, by leaving some of their food reserves under the ground, allow for new trees to germinate.

Yet, few people wish to house a family of squirrels in the attic of their house or to eat in a restaurant where cockroaches have taken up residence. A buyer’s interest in an immovable can suddenly decrease if he spots ant traps during the visit.

Fortunately, preventive measures and control methods exist to avoid damage caused to an immovable due to unwanted guests.

Preventive measures and control methods

According to the Ministère des Forêts, de la Faune et des Parcs, measures to prevent wildlife damage that work on the environment or the animals themselves have several advantages. They can be implemented before the animals cause damage, deal with several species at once, and prevent the development of harmful behaviours.

This last point is very important. Animals that have developed bad habits are known to be much more difficult to control. However, these measures do not eliminate the animal itself, which can migrate and cause damage elsewhere.

The first measure is to change our own habits, which is sometimes enough to solve the problem. For example, by using appropriate containers to dispose of waste, homeowners can prevent animals from getting into the garbage.

The second measure is exclusion. It consists in creating obstacles to prevent animals from entering, such as fencing a field, installing wire mesh around trees, or caulking the entrances to a building.

The third measure consists in modifying the animal’s natural habitat in a way that encourages the presence of its predators, or to carry out work to keep the animal at bay. The idea is to keep the animal away by modifying the environment in a way that makes it unappealing to the animal.

The final method consists in repelling the animal with the use of repellents. These are products or items that work on the animal’s senses. They can be visual (scarecrows), sonic (propane cannons), odoriferous (naphthalene), or gustatory (thiram).

When prevention measures prove ineffective, control methods such as removal are applied.

In most cases it is recommended to use the services of a pest control company in order to resolve the issue safely. Animals can carry diseases that are transmissible to humans. In addition, the chemicals required may be regulated and, in some cases, may only be used by accredited pest control companies. Also, depending on the problem and the methods used to deal with it, certain pieces of legislation may apply.

  • Act respecting the conservation and development of wildlife
  • Pest Control Products Act (Canada)
  • Pesticides Act
  • Environment Quality Act
  • Municipal by-laws
  • Etc.

Emerald ash borer

Some insects attack trees rather than buildings. This is the case with the emerald ash borer. (Click here for more information about this small insect that is doing major damage).



When taking up the brokerage contract, the broker must ask the seller about pests and damages caused by wildlife. In the event that a problem of this nature has occurred in the past and has been resolved, the broker must recommend that his client disclose the nature of the problem and the solution used to any potential buyer, and provide reports and invoices if such documents are available. These declarations must be included in the form Declarations by the seller of the immovable in the case of a residential building containing fewer than five dwellings.

If the problem has not been solved, the broker must recommend that his client retain the services of an expert.

To choose a pest control company, residents can visit the websites of the Ministère de l’Environnement et de la Lutte contre les changements climatiques or the Association Québécoise De La Gestion Parasitaire to verify if the company chosen holds a valid permit for the use of pesticides and if the work will be carried out by a certified employee.

The other element to consider in choosing a company is the nature of the immovable:

  • Agri-Food
  • Pharmaceutical
  • Commercial
  • Agricultural
  • Industrial
  • Residential

It is important to make sure that the company has expertise with the type of immovable where the procedure will be carried out.

A broker representing, or providing fair treatment to, a buyer must read the Declarations by the seller of the immovable and exercise due diligence, including by having the immovable inspected by a professional, in order to correctly assess the problem and make sure it is corrected.

For more details:

Last updated on: November 29, 2021
Reference number: 208813