Professional Ant Killer: What Exterminators Use to Kill Ants in Canada

TL;DR

• Professionals usually use slow-acting baits first (UC IPM says baits are more effective and safer than sprays) and save sprays and dusts for the spots baits cannot reach.
• The usual toolbox: gel baits, liquid baits, bait stations, granular baits, residual sprays and dusts.
• Baits reach the colony: workers eat them, return to the nest and share them with the queen and larvae. Spraying where you see trails can make the colony split, as UC IPM warns for pharaoh ants.
• Common active ingredients include imidacloprid, thiamethoxam, spinosad, abamectin and borates.
• Always look for a PCP number on the label, and don't make homemade boric acid baits (Health Canada).
• Need help? Get a quote from a recommended local exterminator through Pest Agent's referral form.

A professional ant killer is rarely the stronger spray most people picture. What an exterminator puts down for ants is usually a slow bait that the workers carry home, and its power comes from reaching the queen and larvae rather than from wiping out the line of ants on the counter.

That matters if you are weighing a service call against a trip to the hardware store. Several store-bought baits in Canada contain the same active ingredients as the products technicians use, sold in small packages for home use.

Other baits stay off the table for homeowners, whatever their strength: their Canadian label restricts them to licensed applicators.

What Is a Professional Ant Killer?

A professional ant killer is a commercial-class insecticide that only trained, licensed applicators may use in Canada. The product itself is often not much stronger than a store bait. What changes is the formulation, the label, and the training of the person applying it.

Commercial Class Versus Domestic Class

Commercial class and domestic class are two of the four federal classes for pesticides in Canada (the others are manufacturing and restricted), and the class is printed on the front panel of the label. According to Ontario's pesticide classification, a commercial product "can only be used by trained persons including certified farmers, licensed exterminators and permit holders," while a domestic product is used by the general public in and around their homes, and Health Canada notes that provinces are responsible for licensing professional pesticide users. When people search for a professional ant killer, they usually mean a commercial-class ant bait, gel or spray.

Who Can Use a Professional Ant Killer

A professional ant killer can only be applied by someone holding the right provincial certificate or licence. The Canadian label of Maxforce Quantum Ant Bait, for example, reads: "Only to be used by individuals holding an appropriate pesticide applicator certificate or license recognized by the provincial/territorial pesticide regulatory agency where the application occurs." In Ontario, applying pesticides commercially requires a pesticide exterminator licence, and structural extermination is one of the licence types.

Why Professional Ant Killers Work Better

Professional ant killers work better because they are built to reach the colony, not just the ants you see. Most are slow-acting baits: foraging workers eat them, return to the nest and share the bait with the queen and larvae through food exchange (trophallaxis), as the Canadian labels of Maxforce Quantum and Optigard Ant Gel Bait describe. Health Canada explains that a bait must work slowly enough to be fed to all members of the nest. Fast sprays do the opposite: spraying indoors where you see trails can make the colony split into several new colonies. For the full service, from inspection to follow-up, see our guide to ant pest control.

What Do Professionals Use to Kill Ants?

Professionals use slow-acting baits first and save sprays and dusts for the spots baits cannot reach. Canadian companies such as Orkin Canada, Terminix Canada and Pesticon (commercial) all list the same toolbox: gel baits, liquid baits, bait stations, granular baits, residual sprays and dusts.

Gel Baits

Gel baits are the most common professional ant killer indoors. The technician places small dots of gel in cracks, crevices and along trails, where ants feed without being disturbed. Optigard Ant Gel Bait, a commercial-class gel registered in Canada, is labelled for sugar-feeding ants that invade buildings, indoors and outdoors.

Liquid Baits

Liquid baits suit ants that prefer sweet liquids. Maxforce Quantum Ant Bait has a syrup-like texture, and its Canadian label says it resists drying out and stays palatable to ants for up to 3 months indoors. Envu Canada describes it as a product for quarterly service visits. Scorpio PCO Liquid Ant Bait is another commercial liquid bait sold to Canadian professionals.

Bait Stations

Bait stations hold gel or liquid bait inside a closed container. Professionals use them wherever children, pets or wildlife could reach the bait. The Optigard label requires tamper-resistant stations in those areas, and Health Canada advises placing stations in the path of foraging ants, out of reach of children and pets.

Granular Baits

Granular baits are pellets scattered outdoors, around foundations, nests and lawns. Avert Granular Carpenter Ant Bait and Scorpio PCO Ant Bait and Insect Bait are commercial granular baits registered in Canada.

Residual Sprays

Residual sprays leave a thin layer of insecticide that keeps working after it dries. Professionals apply them as spot, crack and crevice, or void treatments, and sometimes on the outside of the building. Temprid SC, for example, combines a fast-acting pyrethroid (beta-cyfluthrin) with imidacloprid for longer control (Envu Canada). Many store sprays contain permethrin or pyrethrins, sometimes with piperonyl butoxide, a synergist that, according to the National Pesticide Information Center (NPIC), blocks insect enzymes so the insecticide has more time to work.

Sprays have limits. NC State Extension says spraying only repels ants, and UC IPM notes that spraying around the foundation won't provide permanent control and that barrier sprays sometimes trap ants indoors. Its advice: ask a pest control company to use baits and spot treatments rather than perimeter treatments or monthly sprays.

Insecticide Dusts

Insecticide dusts are fine powders puffed into wall voids, cracks and crawl spaces. Ants walking through pick up the dust on their legs and antennae and spread it in the colony (Orkin Canada, commercial). Diatomaceous earth is one non-chemical dust: NPIC explains that it dries insects out by absorbing the oils and fats of their outer shell, and Health Canada notes it will remain active as long as it is kept dry. Health Canada calls it non-toxic to humans and pets but warns not to inhale the dust.

How Fast Baits Work

Baits work over days to weeks, not minutes. You may see more ants at first, because workers recruit nestmates to the food. UC IPM says it can take 5 to 10 days to see fewer ants, and full control may take several weeks or more. The Canadian Scorpio PCO label says it starts killing within 24 hours, and NC State Extension says complete eradication can take one to two weeks. Health Canada recommends keeping baits out for at least two weeks and not spraying while baits are in place. For carpenter ants, it also advises leaving dead ants where they are, because other ants may carry the insecticide back to the colony.

Which Active Ingredients Are in Professional Ant Killers?

Professional ant killers in Canada mostly rely on a handful of slow-acting active ingredients. Here are the ones you will see on Canadian professional labels, with their Pest Control Products (PCP) registration numbers from Health Canada's label search.

Imidacloprid

Imidacloprid is a nerve poison: NPIC explains that it disrupts the nerve's ability to send a normal signal, and that it binds better to the receptors of insect nerve cells. Maxforce Quantum Ant Bait (PCP 30513, commercial class) contains imidacloprid 0.03%. Its label lists Argentine ants, black garden ants, ghost ants and pharaoh ants, but excludes fire, harvester and carpenter ants.

Thiamethoxam

Thiamethoxam is the active ingredient of Optigard Ant Gel Bait (PCP 30788, commercial class), at 0.01%. The label targets sugar-feeding ants and says ants feeding on the bait may return to the nest and pass it to other workers, the queen and the larvae.

Spinosad

Spinosad is a natural substance made by a soil bacterium. According to NPIC, it attacks the nervous system of insects that eat or touch it, causing paralysis and death, often within one to two days. Scorpio PCO Liquid Ant Bait (PCP 32759, commercial class) contains spinosad 0.015%, and its label lists carpenter, pharaoh, little black, Argentine and moisture ants among others.

Abamectin

Abamectin is used in professional carpenter ant baits. Avert Granular Carpenter Ant Bait (PCP 27864) and the Avert 360A Dual Choice Ant Bait Station (PCP 27897) both contain abamectin 0.011% and are commercial class.

Borates

Borates (boric acid, borax and disodium octaborate) are classic ant bait ingredients. NPIC explains that boric acid kills insects that eat it by disrupting their stomach, and it can also affect their nervous system. Drax Ant Kil Gel (PCP 20478) is a commercial gel with boric acid 5.0%, and many store baits use borax. Our guide to boric acid for ants covers how these baits work.

Hydramethylnon

Hydramethylnon is a slow-acting bait ingredient that stops ants from turning food into energy. Many older and US guides still name it as a top professional ant killer, and the City of Calgary lists it among baits that slowly eliminate the colony. However, Health Canada's pesticide registry, checked in October 2026, lists every hydramethylnon product, including the Maxforce Ant Control System and Combat Ant Killing System, as historical, not registered.

Ingredients on US Labels

Fipronil and indoxacarb are two ingredients you will often read about on US sites. UC IPM names fipronil among the more effective materials professionals have access to, and Syngenta's Advion Ant Gel (indoxacarb) is a widely used US professional gel. Products sold in the US are not always registered here, so before you buy any ant killer online, check that its label shows a Canadian PCP number.

What Do Exterminators Use for Different Ant Species?

Exterminators choose the product by species, because each ant reacts differently to baits and sprays. A product that wipes out one species can sometimes make another split into new nests, which is why a good technician identifies the ant first. Our ant hub has guides for each common species.

Carpenter Ants

Carpenter ants usually need the nest itself to be treated. Health Canada notes that you usually need to locate and treat the actual nest site for long-term control, and that the parent colony should be found and destroyed. Exterminators often combine treating the nest directly with baits labelled for carpenter ants, such as Avert or Scorpio PCO, and NC State Extension says effective control often requires treating the nest. Note that Maxforce Quantum is not labelled for carpenter ants. Winged ants indoors are often the first sign: see our guide to flying ant exterminators and our page on carpenter ant pest control.

Pharaoh Ants

Pharaoh ants get bait only, never repellent sprays, which UC IPM says are not effective for them. Alberta Health warns that insecticidal sprays can make a pharaoh ant colony bud (split into new nests), and Pesticon (commercial) says it uses slow-acting bait for them. Maxforce Quantum and Scorpio PCO both appear to list pharaoh ants on their Canadian labels. Learn how to recognise them in our guide to pharaoh ants.

Sugar-Feeding Ants

Sugar-feeding ants, such as odorous house ants and little black ants, are usually treated with gel and liquid baits. The University of Kentucky describes odorous house ants as difficult for homeowners to control, because they have multiple queens and their colonies can split. Pesticon (commercial) pairs baits with removing the moisture source that draws them in.

Pavement Ants

Pavement ants can nest under stones, pavement cracks and building foundations (Utah State University Extension), so professionals treat the edges of slabs and foundations where the ants come in (Pesticon, commercial), along with baits placed on their trails.

European Fire Ants

European fire ants sting, and they have been established in British Columbia since about 2010, according to the Invasive Species Council of BC. Its advice is clear: if you find a nest, do not try to remove it yourself. A licensed professional is the right call for this species.

Can You Buy a Professional Ant Killer in Canada?

You generally cannot legally use a commercial-class ant killer at home without the right licence, but domestic products with the same active ingredients are sold in Canadian stores. The difference is usually the concentration, the format and the label directions.

Domestic Ant Killers With Professional Ingredients

Domestic ant killers often share the active ingredient of a professional product. In Health Canada's label search, Raid Max Liquid Ant Baits (PCP 33831) and Neudorff Liquid Ant Bait Station (PCP 33096) contain spinosad 0.015%, the same concentration as the commercial Scorpio PCO bait. Raid Ant Baits (PCP 32316) contain abamectin 0.05%, and TERRO liquid ant baits (PCP 30897) contain borax 5.4%. These sealed stations are designed for homeowners. For tested picks, see our best ant killer roundup.

How to Read an Ant Killer Label

An ant killer label tells you everything you need to use it legally. Health Canada advises always looking for a PCP number, which shows the product is approved for sale in Canada, and following all label directions and warnings. Check three more things: the class (domestic or commercial), the species listed (TERRO's product page, for instance, says its liquid baits are not for pharaoh, carpenter, fire or harvester ants), and the restrictions around children and pets. If you have animals at home, read our guide to pet-safe ant killers.

Homemade Boric Acid Baits

Homemade boric acid baits are not a substitute for a professional ant killer. Health Canada asks people not to make homemade pesticides using boric acid and now allows domestic boric acid products only as sealed bait stations or localized gels, because children are at the highest risk of poisoning. A registered bait station gives you the same ingredient in a safer format.

Ultrasonic Repellers

Ultrasonic repellers are not part of a professional ant control toolbox. Older advice lists them as an advanced technique, but extension specialists disagree: University of Arizona Cooperative Extension notes that researchers have concluded these devices do not effectively repel or eliminate pests from homes and gardens, and a Washington State University Extension bulletin reaches the same conclusion.

When to Hire a Professional

Hiring a professional makes sense when baits have not worked after a few weeks, when you see signs of carpenter ants in the wood, when ants appear in several rooms or units, or when you find a European fire ant nest. Health Canada recommends a professional exterminator for difficult carpenter ant situations. In Quebec, the contract may need to list the exact product names and registration numbers, and anywhere in Canada you can ask which registered products will be used. To compare prices, read what ant extermination costs in Canada. You can also get a quote from a recommended local exterminator through Pest Agent's referral form.