More than 100 species of ants are found in Canada. Among these, 7 cause the most problems in buildings and backyards. It’s important to know which ant is causing your ant problem because they’re not all controlled the same way.   

Carpenter ants are one of the most difficult ants to control. (For tips, read How to Get Rid of Carpenter Ants) For the best results, use a combination of ant control products: 

• Ant repellents – Available as aerosols, foams, sprays and organic sprays, these products kill ants on contact and are most effective when applied directly to the carpenter ant nest. They also create a defensive barrier that carpenter ants will not cross. 
• Ant traps – Ant traps (also known as bait stations) are filled with an insecticide bait. Foraging ants take bait back to the colony where it is shared among the workers, larvae (baby ants) and queen. Ant traps are a good option if you cannot locate the nest. Ant traps are designed for indoor or outdoor use. Learn more about ant traps and insecticide bait and how to use them.
• Diatomaceous Earth – Often called DE ant powder or DE ant dust, this natural desiccant kills ants by drying them out. It is applied to indoor areas where ants are active. The ants walk through the DE, which scratches the waxy outer layer of their exoskeleton. This causes the ant to dry out and die. DE will not kill the colony, but it will reduce the number of foraging ants. Learn more about DE and how to apply it. 

PHARAOH ANTS
It is essential to use the right pest control products to kill pharaoh ants or you will make the ant problem worse:

• Ant traps – The best ant killers for pharaoh ants are ant traps (also called ant bait stations), which are filled with an insecticide bait. Foraging ants take the bait back to the colony where it is shared among the workers, larvae (baby ants) and queens. To eliminate pharaoh ants, you must kill the queens. Place ant traps where pharaoh ants are active, such as under sinks. Slow-acting bait gets the best results. Learn about ant traps and insecticide bait and how to use them.
• Diatomaceous Earth – Also called DE ant powder or DE ant dust, DE can help reduce the number of foraging pharaoh ants, but it will not kill the queens or colony. Apply it to wall voids, behind baseboards and cabinets where the ants are active. The ants will walk through this natural desiccant, which scratches the waxy outer layer of their exoskeleton, causing them to dry out and die. Learn more about DE and how to apply it.
• Ant repellents – They are not recommended for use on pharaoh ants because they will cause the colony to panic and split into multiple nests, ultimately creating a bigger ant problem.  

To eliminate pavement ants, use a combination of DIY ant control products:

• Ant traps – Ant traps (also called ant bait stations) are filled with an insecticide bait. Foraging ants take bait back to the colony where it is shared among the workers, larvae (baby ants) and queen.  Ant traps are designed for indoor or outdoor use. Learn more about ant stations and insecticide bait and how to use them.
• Diatomaceous Earth – Often called DE ant powder or DE ant dust, this natural desiccant kills ants by drying them out. It is applied to indoor areas where ants are active. The ants walk through the DE, which scratches the waxy outer layer of their exoskeleton. This causes the ant to dry out and die. DE will not kill the colony, but it will reduce the number of foraging ants. Learn more about DE and how to apply it.
• Ant repellents – Available as aerosols, foams, and organic and non-organic sprays, these products kill ants on contact and are most effective when applied directly to the ant nest. They also create a defensive barrier that pavement ants will not cross. 

To eliminate thief ants, use a combination of pest control products:

• Ant traps – Ant traps are filled with an insecticide bait. Foraging ants take bait back to the colony where it is shared among the workers, larvae (baby ants) and queen. Ant traps (also called ant bait stations) are a good choice when you have an indoor thief ant nest that is difficult to locate. Ant traps also can be used outdoors. Place traps near thief ant nests or trails. Learn more about ant traps and insecticide baits and how to use them.
• Diatomaceous Earth – Often called DE ant powder or DE ant dust, this natural desiccant kills ants by drying them out. Apply it to indoor areas where ants are active, such as in wall voids behind electrical outlets and where plumbing and wiring enter walls. The ants walk through the DE, which scratches the waxy outer layer of their exoskeleton. This causes the ant to dry out and die. DE will not kill the colony, but it will reduce the number of foraging ants. Learn more about DE and how to apply it.
• Ant repellents – Available as aerosols, foams, sprays and organic sprays, these products kill ants on contact and are most effective when applied directly to the thief ant nest. Repellent sprays also create a defensive barrier that the ants will not cross. However, if the thief ant colony has more than one queen, the indiscriminate application of repellent – while killing a few ants -- may cause the colony to panic and split into multiple nests, creating a bigger ant problem. Learn more about thief ants, ant repellent and how best to use it.

LITTLE BLACK ANTS
To eliminate little black ants, use a combination of pest control products:

• Ant traps– Ant traps are filled with an insecticide bait. Foraging ants take bait back to the colony where it is shared among the workers, larvae (baby ants) and queen. Ant traps, also called ant bait stations, can be used indoors and outdoors. Place traps where the ants are trailing and near nests. Learn more about ant stations and insecticide baits and how to use them.
• Ant repellents – Available as aerosols, foam, foggers, sprays and organic sprays, these products kill ants on contact and are most effective when applied directly to the little black ant nest. Drench outdoor nests with liquid repellent. Use an aerosol or foam to kill ants nesting in the wall. Repellent sprays also create a defensive barrier that the ants will not cross.
• Diatomaceous Earth – Often called DE ant powder or DE ant dust, this natural desiccant kills ants by drying them out. Apply it to indoor areas where ants are active, such as in cracks and crevices and wall voids where plumbing and wiring penetrate walls. The ants walk through the DE, which scratches the waxy outer layer of their exoskeleton. This causes the ant to dry out and die. DE will not kill the colony, but it will reduce the number of foraging ants. Learn more about DE and how to apply it.

ODOROUS HOUSE ANTS 
It is essential to use the right pest control products to kill odorous house ants or you will make the ant problem worse: 

• Ant traps - The best ant killers for odorous house ants are ant traps (also called ant bait stations), which are filled with an insecticide bait. Foraging ants take the bait back to the colony where it is shared among the workers, larvae (baby ants) and queens. To eliminate odorous house ants, you must kill the queens. Place ant traps where the ants are trailing and near nests. Use slow-acting sugar- and protein-based baits. Learn more about ant stations and insecticide baits and how to use them.
• Diatomaceous Earth (DE) - Also called DE ant powder or DE ant dust, DE can help reduce the number of foraging odorous house ants, but it will not kill the queens and may make the colony panic and split. It is best applied to wall voids, behind baseboards and cabinets where the ants are active. The ants will walk through this natural desiccant, which scratches the waxy outer layer of their exoskeleton, causing them to dry out and die. Learn more about DE and how to apply it.
• Ant repellents - Repellents are not recommended for use on odorous ants because they will cause the colony to split into multiple nests, ultimately creating a bigger ant problem.  

It is important to use the right pest control products to kill European fire ants or you will make the ant problem worse:

• Ant traps – The best ant killers for European fire ants are ant traps (also called ant bait stations), which are filled with an insecticide bait. Foraging ants take the bait back to the colony where it is shared among the workers, larvae (baby ants) and queens. To eliminate European fire ants, you must kill the queens. Place ant traps outdoors where the ants are active and near nests. Use slow-acting sweet- and fat-based insecticide baits. Learn more about ant traps and insecticide baits and how to use them.

Read more: 

How ant traps work

What are Insecticide Baits?