How to fight back against fire ants

Fire ants are a growing problem in the Halifax area, but one researcher has a new idea on how to exterminate the backyard pests.

The European fire ant is an invasive insect that aggressively defends its territory, even stinging humans and pets. The ants nest in soil, under rocks and in decaying logs, and spread easily.

Susan Horton has been studying fire ants for the past few years as they spread throughout Halifax. She's studying ways to wipe them out.

"Once you notice them, they will only increase," she said.

"They have multiple queens and they have multiple nests, which gives them a bit of an edge in success. Because there's just so many of them. You're fighting a lot."

Horton is testing her theory that to exterminate fire ants people have to remove their entire nests.

The task is easier said than done, she says

"They're hard to see. Just looking at the lawn, this is like an every day lawn, you can't tell where the nests are, there are no mounds. So it's basically a sweep where you go in one direction and you check with your feet, you can hit the ground with your trowel."

Nests are usually around structural pieces, like wood beams, and can be a metre long. Horton says they'll have a white larva and a queen — she's bigger than the rest, and sometimes has wings.

Getting rid of the nests can mean digging up an entire lawn, and the surrounding lawns as well.

"You keep on going until there's hardly any activity, which is going to take a while," said Horton.

There is no municipal, provincial or federal funding available to manage the problem in Halifax.

Richard Maclellan, the manager of the city's Sustainable Environment Management Office, says Halifax doesn't have an active plan to deal with fire ants.

"As we gain information we're keen to continue to share that information that we learn," he said.