Ants (General) - What are they?

Ants may be black, brown, red or yellow. Adult ants range in size from as small as 1 millimetre (1/16 to 1/32 inch, e.g. little black ants and thief ants) to as large as 13 millimetres (1/2 inch) (e.g. carpenter ants).

Ants create new colonies by a process of swarming or budding. The appearance of winged queens and smaller winged males means that swarming is taking place. The ants may come indoors at this time, but this does not necessarily mean that the ants will succeed in colonizing in your home.

Depending on the species, a colony is made up of one or more queen and worker ants. The queens lay the eggs while the workers defend the nest, care for larvae (hatched eggs) and forage for food. The workers carry food back to the nest to feed the queen, larvae and pupae (developing young ants).

Carpenter ants are larger than other species although the sizes of the workers vary. They can cause structural damage to homes as they destroy wood to make room for their nests. Piles of sawdust may indicate you have carpenter ants (for further information please refer to Carpenter Ants).

Carpenter ants are sometimes confused with termites, but it is easy to distinguish between them: the termite has straight antennae and a thick waist, and the carpenter ant has a very narrow waist and “elbowed” antennae. Termites are present only in specific areas in Canada.

The species of ants commonly found in Canada are not aggressive, although some can sting. Ants should be tolerated as much as possible as they cause little damage in the garden. They can even be considered beneficial because they eat other insects such as young silverfish and moths.

Species that are known to invade homes in Canada may include the carpenter ant, the little black ant, the odorous house ant, the thief ant and the pharaoh ant.

Pavement ants can become a nuisance in lawns, gardens and pathways as well as indoors.

Ant colonies send out scouts to forage for food. A successful scout leaves a scented trail for other workers to follow back to the food source. Removing access to food and water is the easiest way to avoid all pest problems. Ants are attracted to many types of food. They enjoy eating sugary and greasy foods like peanut butter or crumbs and are also attracted to the “honeydew” produced by aphids on infested houseplants.

  • Store ant-attractive foods in glass jars with rubber gaskets or in plastic containers with lids that snap tight.
  • Keep kitchen countertops clean.
  • Sweep or vacuum the floor frequently, especially around pet dishes.
  • Rinse containers before disposing of them in the garbage or in recycling bins.
  • Empty kitchen garbage containers frequently.
  • Place composters at a reasonable distance from the house.
  • Repair and seal as many visible cracks in the foundation and exterior walls of your house as possible.
  • Indoors, caulk along baseboards, cracks and crevices to keep the ants from passing through your house–if necessary, use duct tape or petroleum jelly to temporarily seal cracks.
  • Ants will not cross sticky barriers–try placing two-sided tape around the legs of plant stands.
  • Place pet dishes in a shallow dish of water. Ants can’t swim, so they won’t be able to get at your pet’s food.
  • Flood ant nests repeatedly with a garden hose to encourage the ants to move farther away from the house.
  • Pour boiling water and detergent down the nest to temporarily reduce the population of a colony.
Source: Health Canada – Ants – Pest Note
© Her Majesty the Queen in Right of Canada, represented by
the Minister of Health Canada, 2009
HC Pub: 8200
ISBN: 978-1-100-12301-1 (978-1-100-12302-8)
Catalogue Number: H113-1/1-2009E (H113-1/1-2009E-PDF)