As Canadian summers become increasingly hot, the rise in temperatures means some indoor-restrictive ant species could soon move outdoors, allowing these small pests to spread at a much faster rate.
According to a new study by the University of Toronto Scarborough, certain ant species that can survive indoors in cooler areas are beginning to move outdoors due to warmer temperatures resulting from climate change.
“What our research has found, that under climate change, the winter is expected to get warmer, making it more favourable for these, currently indoor-restrictive ants, to survive,” said Toby Tsang, a postdoctoral researcher at the University of Toronto Scarborough.
“In other words, that means climate change can increase the number of non-native ants in the wild in Canada.”
Tsang is the lead author of the study. His research found that as temperatures rise by 2 degrees C to 4 degrees C due to global warming, alien species of ants, which were originally restricted to indoor environments in the Northern Hemisphere, are more likely to move to outdoor environments.
Tsang researched 323 alien ant species in 477 regions around the world and found that at least five alien ant species have invaded Canada and mainly live indoors. However, if any one of them begins to spread outdoors, it is likely to cause agricultural damage in addition to causing bodily harm.
“Under climate change, they might start finding outdoor environments to become more suitable for them. So, they may start occupying the outdoor environment as well,” Tsang said.
Among these pests is the “little fire ant,” also known as the “electric ant,” native to Central and South America. It’s categorized as one of the world’s 100 invasive species by the International Union for Conservation of Nature. This amber-coloured ant is now found in Canada, but it remains unclear how these small ants made their way into the country.
“We don’t actually know how they were introduced to different regions in the first place, for non-native ants. What we do know is that a lot of them right now are established in Canada,” Tsang said.
The little fire ant is found indoors in Ontario, Quebec, British Columbia, and Manitoba. But the non-native ant has become more common because it’s able to migrate outdoors and reproduce.
“A lot of these non-native ants are introduced unintentionally,” Tsang said, explaining they can hide and naturally survive in potted plants and potted soil and be carried from one destination to another by hiding in shipping containers, vehicles and even luggage.
The little fire ant can also cause pain with bites that could feel like an electric shock.
“The little fire ants mainly sting people and is very painful. But some people, have reported to have some sort of allergic reaction. So, that’s why non-native insects or non-native ants can also be a public health concern,” Tsang said.
Tsang cautioned to avoid contact with swarms of ants, whether indoors or outdoors, and consult a pest control specialist for help when trying to get rid of them. Engagement with swarms of ants can cause disruption and lead to an attack.
“Even for us, we cannot identify the ant species just based on the naked eye, so that’s even more difficult for the public,” Tsang said, “What I would recommend is that if you find, like your house has been infested by ants, it’s better not to touch them or try to get rid of them on your own.”
With files from Grace Lin, OMNI News and the University of Toronto Scarborough
