Ants: An Old Nemesis and New Challenges

Editor’s note: This article previously appeared in an issue of PCT Canada. To learn more, visit www.pctonline.com/page/pct-canada.

Ant control is the bread-and-butter of most pest control companies, with spring and early summer the busiest times of year for this service.

The height of COVID-19 threw what’s usual right out the window. Instead of calling for service, many customers were holding off on ant treatment or asking for bait-only treatment so they didn’t have to leave their homes during the lockdown following the application of a liquid insecticide, said Paolo Bossio, president of Advantage Pest Services in Scarborough, Ontario. And that March when we interviewed pest management professionals, it was still too cold to perform exterior-only ant treatments.

“It’s a little daunting trying to get this type of work done,” admitted Bossio.

Many pest management professionals expected — and did receive — pent-up demand and calls for ant control once the pandemic crisis turned the corner.

In Halifax, Nova Scotia, Truly Nolen franchise owner Andrew Wheelock always plans for a robust ant control season, pandemic or not.

He said ants are a big part of his business.

“They’re a great opportunity for us to garner new business and create relationships on a prevention basis,” he said.

PMPs identified two ants sure to cause problems any spring/summer season, as well as tips for controlling them. The first is a common adversary: the carpenter ant. The second are similar imported species causing an increasing number of issues in multi-tenant properties across Canada: Pharaoh and thief ants. An overview of each follows.

CARPENTER ANTS. “My best friend and biggest nemesis would be carpenter ants,” said Bossio. “It’s the job we like doing the most. They’re definitely our best friend in this industry and also very difficult to get rid of.”

Carpenter ants are challenging to control because a structure may contain one or more satellite nests, yet it’s impossible to see through the walls to learn where those nests reside. Moisture and wet wood attract the ants, but nests may be located some distance from these sites.

Nicholas Holland, owner of Peregrine General Pest Control in Calgary, Alberta, found a nest in the wood timbers in the middle of a basement ceiling, far from a moisture-damaged window casing.

In addition, the primary colony likely is located somewhere outside. Control can be particularly difficult at homes on large wooded lots.

“That’s when you get the doozy carpenter ant jobs,” Holland said. “You have satellite colonies all interconnected and the carpenter ants don’t really care where the neighbor’s property starts or ends. It takes multiple applications and a lot of investigative time on site trying to figure it out.”

Some companies fail by not spending enough time investigating and asking clients where they’ve seen the ants.

“The longer you spend with the client talking about the issue or even investigating it onsite, the higher the chances of eradicating the problem,” said Bossio.

PMPs said children and people who spend the most time at the home, such as nannies and other caregivers, may have more insights to share than the actual homeowner.

The key is not taking a cookie-cutter approach to carpenter ant jobs. Advantage Pest Services promotes a “dynamic IPM” or integrated pest management approach that differs case by case, said Bossio.

“We try to be dynamic in our processes, and we try not to be rigid; just be fluid in every situation,” he explained.

Maheu&Maheu, based in Québec City, has specialized carpenter ant crews. These teams perform only carpenter ant work from April through September. This makes it easier to schedule the time- consuming jobs and the technicians get “better and better” at solving carpenter ant problems. Plus, most of the technicians are seasonal employees who come back year after year, explained General Manager Michel Maheu.

“This has been working great for us,” he said.

To avoid making holes in walls to find satellite nests, Maheu&Maheu relies on ant baits to control the pests. In early spring before leaves appear on the trees, the ants emerge indoors looking for food.

“The sooner in the season you can get there with your baits, the better chances you’ll have to succeed because you’ll create the trailing behavior to your bait,” said Maheu.

Once the trees have leaves, and caterpillars and other insects appear, the ants switch to a protein diet and start moving outdoors to forage. At that point, successful baiting becomes much more difficult.

Through the years, Maheu has observed that carpenter ant colonies become active at the same time each year.

“They’re really good clocks,” he said.

For instance, if ant activity began at a house in mid-February this year, it is very likely activity will start again at that same time next year if the satellite nest is not eradicated, he explained. This is how Maheu verifies the efficacy of his control program and provides a two-year guarantee.

“If there’s no activity at the anniversary date of the start of the program, that’s a very good indicator,” he said.

Once the ants in the walls are eradicated, apply an exterior barrier treatment. This should protect the structure “so hopefully the customer doesn’t experience any colonization in their house in the future,” said Wheelock.

PHARAOH/THIEF ANTS. Pharaoh and thief ants aren’t from around here. They’re imported. Yet, across Canada, pest management professionals are finding more of them in multi-tenant dwellings where they’re posing a significant challenge.

“Pharaoh ants have made a great appearance here in this province,” said Taz Stuart, director of technical operations at Poulin’s Pest Control in Winnipeg, Manitoba. “We’re starting to see Pharaoh ants in places where there hadn’t been Pharaoh ants ever.”

Stuart said calls for the ants are increasing. Before 2016, he got one to two service requests for these ants in a 10-year period.

“Now we’re in the dozens, maybe more,” he said.

As such, Stuart urged pest management professionals to be aware of their presence.

The ants likely are brought into buildings in tenant belongings.

“I do believe Pharaoh ants are coming in with our new Canadians,” said Stuart.

Once introduced, the ants quickly become established, and when residents try to control the pests themselves with over-the-counter sprays, the multi-queen colonies split off or bud, creating an even bigger problem.

Maheu considers Pharaoh ants one of the “most challenging” to control in the Montréal metropolitan area.

He doesn’t come across the ant often because his clients are predominantly food plants, not multi-unit residential buildings. Still, he’s learned “if it’s a multiple apartment building it can be a nightmare” to control because colonies can split multiple times creating an even greater number of colonies throughout the structure.

“It becomes never ending,” said Maheu of the control challenge.

The colony even may bud if residents clean with bleach and antiseptic sprays too close to the primary colony.

“They don’t realize they’re creating a bigger problem,” said Stuart.

The first step in controlling these ants is proper identification. In 2019, Holland thought he had a Pharaoh ant infestation at a 12-story apartment building, but it turned out to be thief ants, a similar imported species that also has multiple queens and forms new colonies when disturbed. Entomologists at the National Pest Management Association helped him positively identify the species.

Rob Higgins, an ant specialist at Thompson Rivers University in Kamloops, British Columbia, urged pest management professionals to make sure pavement ants (Tetramorium immigrans) aren’t being mistaken for thief ants (Solenopsis molesta), as pavement ants are “all over southern British Columbia these days” and are “definitely a problem in apartments.”

Proper ID is crucial because if an ant is not listed on a chemical control product label, that product cannot be used to control the ant.

In interviews, PMPs said they’ve had success using baits to control Pharaoh and thief ants in multi-unit housing. That’s mainly because Canada does not have a non-repellent spray labeled for the pests (PMPs in the United States do have access to non- repellents for ants) and the available repellent sprays can cause the colonies to bud.

Wheelock used a slow-acting liquid ant bait containing Boron and honeydew bait matrix to treat Pharaoh ants at a 90-unit apartment complex in Halifax.

“It shockingly did well,” he recalled.

But you have to take an entire-building approach, not just treat a few of the units.

“The broader you can go in your application, the better you’re going to be when it comes to Pharaoh,” said Wheelock.

Higgins agreed. Control generally requires “baits as broadly distributed as possible,” he said.

And for the ants to take the bait, units must be “hospital clean,” said Stuart. “People can’t leave out the water sources, the food sources, because Pharaoh ants can get into anything.”

Holland used hundreds of monitors to track activity of the nocturnal pests. He rotated the use of several ant gel baits and also used dust.

“Once we started dusting and taking off electrical outlets and things of that nature, that’s when we started to get success,” said Holland.

Stuart, however, remains cautious about using dust insecticides, as they may cause a colony to bud. All of this, including the detective work required to follow ant trails to nests, takes time.

“It may take six months or a year to solve a Pharaoh ant issue in certain buildings just based on tenant cooperation,” said Stuart.

And technicians may need access to apartments to check baits and monitors every seven days or so. The level of buy-in required can be a real “reality check” for property managers, he said.

Holland called the thief ant infestation one of the “coolest” jobs of his career even though it took six months to solve.

“In the early part of it, our application wasn’t the best,” he said. “By the end of the course, we figured out all our errors. It was a great lesson.”

Stuart, likewise, is enjoying Pharaoh ant work.

“It’s exciting because it’s a whole different protocol,” he said. “When you see Pharaoh ants trailing, it’s like a massive vein or an artery with a massive number of ants coming down a crack or crevice and watching them crawl up into the inside of a peanut butter lid just to get a food source. It’s awesome.”