‘They eat everything’: New type of invasive ant spreading in France

A type of invasive ant is increasingly being reported in gardens across France, with residents saying that they are particularly difficult to deter or kill.

The ants have been reported across the country, from Albi in the south-west (Tarn, Occitanie) to Strasbourg in the north-east (Bas-Rhin, Grand Est). They are thought to have come over from Germany, where they have already become an issue in some towns.

Their ‘official’ name is tapinoma magnum, and they can adapt to different temperatures and seasons.

They form large colonies over several hectares, and can have several queens. This means that - in contrast to other types of ants in which one colony will attack others and naturally regulate ant numbers - these types of ants can proliferate rapidly.

The ants can be tough to get rid of, and can bite humans.

"This ant spreads due to global warming, as it likes hot, dry environments,” said Cyril Berquier, an entomologist (insect expert) at the Corsican Environment Office, to Le Figaro.

"They crawl through windows, get into walls, and eat everything," said one resident to Le Point.

Ants in Germany

The ants were first spotted in France - in Corsica - in 2017. They hit headlines in 2023 when they attacked plants at markets there.

Towns in Germany are currently suffering badly from the ants, including border towns close to France.

“Very common in Africa, they were imported [to Germany and France] by Alsace garden centres that sell exotic plants,” said the environmental department of the Strasbourg mairie, to Le Parisien.

One Franco-German border town in Germany, Kehl, has been suffering from a tapinoma magnum ‘invasion’ for more than a year. A neighbouring village, Marlen, has reported that the ants have destroyed a football field, chewed through internet cables, and electric wires.

"They destroy public spaces, lawns, roads, and pavements. They even get into the walls," said Gregor Koschate, the town's environment officer, to France Bleu Alsace. 

Difficult to deter

Olivier Blight, a myrmecologist (ant expert) and research professor at the Institut méditerranéen de biodiversité et d' écologie, has admitted that the ants can be persistent. "It's virtually impossible to get rid of them,” he said.

In Albi, residents have reported mixed results when trying to eliminate the insects. 

One resident said that they have found a particular powder that works to keep the ants at bay, but another has said that nothing has worked, and they cannot go outside without being bitten.

In Kehl, authorities have had medium success with a foaming solution, which a specialist company injects - very hot and under pressure - into the anthills. This limits the insects' expansion, although it is expensive.

Now, the city of Strasbourg is set to join with Kehl to invest in a special anti-ant spray tool. 

"We are planning to jointly invest €50,000…to enable Strasbourg and Kehl municipal officers to spray repellents in the streets to eradicate this species, in order to avoid large-scale damage on both sides of the border,” said Annette Lipowsky, chief of staff to the mayor of Kehl.

Experts suggest that it is most effective to attack the ants in spring or in winter, when they are weaker.