Most ants in Vancouver are either pavement ants or carpenter ants. They size from a few millimeters (pavement ants) to about 3/8″ to 1″ (carpenter ants).
They do many good things in the environment but once many colonies stabilize in one area they can create a huge mess and wood boring carpenter ants can cause serious damage in wood structures when an infestation occur. All ants are social insects that work in unison, hence while you see many of them in one colony.
They also share most of their food so Local Pest Control can eradicate your ant problem quickly with the use of environmentally neutral baits.