What do they look like?

The red carpenter ants and the black hornet ants are among the most common species of carpenter ants in Canada. The body of the red carpenter ant is blackish with a thorax colored red or brown. The black spoiler ant, on the other hand, is uniformly black with tints of brown.

Carpenter ants are between 6 mm and 25 mm in length. Its antennae are arched and segmented. Both male and female adults are winged upon mating. Carpenter ants build their nests by boring galleries in the wood. Carpenter ants can become established in homes, attack lumber, and infest spaces between walls, attics or hollow doors.

Carpenter ants are well known to cause damage to wooden structures. Carpenter ants build their nests in wood. They dig galleries much longer than those of termites. Carpenter ants do not eat wood; they throw it out of their galleries in the form of fine shavings that look like sawdust.

Carpenter ants form large colonies made up of hundreds of worker ants (sterile females), several breeding males and females, and one or more queens. Individuals from an established colony may migrate to a nearby structure, forming a smaller satellite colony there.

Outdoors, carpenter ants can lodge in standing trunks of dead trees, in stumps or logs, or under trunks littering the ground or stones. They sometimes dig tunnels in healthy wood, but they generally choose soft wood species such as pine.

Indoors, as they prefer damp, rotten wood, the presence of carpenter ants can indicate a problem with moisture or decaying wood structures. In addition to tunneling through moldings, staircases, and wooden window frames, an ant colony can build its nest in a house without attacking lumber and infesting empty spaces between walls, attics, or lofts, hollow doors. Nests have even been found behind books stored in bookcases, behind dresser or cabinet drawers, and behind styrofoam insulation boards.

Carpenter ants sneak into houses by:

• the Windows;
• cracks in the foundation;
• the ducts of the heating or air conditioning system;
• power or telephone cables;
• the junction points between the house and vegetation such as tree branches;
• wooden structures attached to houses (such as verandas and sheds);
• firewood brought into the house.

To screen for carpenter ants:

• Inspect all areas that are very humid and poorly ventilated;
• Check specific places for large numbers of ants, such as under the kitchen sink;
• It is possible that a trail leads to a mother colony outside the house;
• Watch out for swarms of winged ants that seek to escape outdoors, usually in the spring;
• Watch for accumulations of sawdust-like chips outside ant galleries and cracks in woodwork.