First decide whether you are seeing a nest or normal outdoor activity
A few wasps around flowers, food or recycling do not prove that a nest is on the property. Watch from a safe distance for repeated traffic into one ground opening, wall cavity, soffit, tree or structure. Health Canada notes that social wasp nests can be visible or hidden, so repeated flight to the same point is more useful evidence than the number of wasps seen in the yard.
Location changes the risk
A nest well away from regular activity is a different problem from one beside an entrance, play area or frequently used balcony. Health Canada recommends tolerating small populations when they do not create a health hazard because wasps also have a beneficial ecological role. When a nest does create a hazard, distance, concealment and safe access should drive the response.
Reduce attractants around people
Keep garbage tightly covered, do not leave pet food or picnic food exposed, and keep sweet drinks covered outdoors. Traps can increase wasp activity around the trap, so Health Canada advises placing them away from play areas and other places where people gather.
Do not take unnecessary sting risk
Wasp stings can cause severe allergic reactions in some people. A concealed or elevated nest, a large active nest, or a nest near someone with a known serious sting allergy is a strong reason not to improvise close-range removal. Health Canada recommends professional help for nest removal even though a properly protected homeowner may sometimes be able to remove an accessible nest.
Private property and public property are different routes
A nest on a private house, balcony or yard is usually a property-owner, landlord or building-management issue. A nest in a municipal park, playground, boulevard or other public asset may belong with the municipality. Use the relevant city guide to see whether a local reporting route exists.
If a pesticide is used, the Canadian label still controls
Confirm that the product is registered in Canada for the pest and treatment location and follow the label directions. Do not improvise treatment into wall voids, indoor spaces or inaccessible nests if the product does not authorize that use. Provincial and municipal pesticide restrictions may also apply.