Electric ant: the invasive threat spreading through southern France

Yet another creature we could gladly have done without has established itself in southern France over recent years, and its presence is only becoming more pronounced. These true six-legged micro-tasers could spread further and disrupt ecosystems.

Following the arrival in mainland France of the Asian hornet (Vespa velutina) and tiger mosquito (Aedes albopictus) in 2004, we are now confronted with another invader. Its name is Wasmannia auropunctata, better known as the electric ant or little fire ant - a name that immediately gives an idea of what to expect.

Electric ant: an invasive species spreading through the Var

Native to the tropical forests of South America, this tiny insect, measuring just 1.5 mm, has appeared for several years on the IUCN (International Union for Conservation of Nature) blacklist of the world’s 100 most invasive alien species. It has already taken hold across large areas of central Africa, Pacific islands and parts of the Mediterranean basin, and it has now been present in the Var since 2022. It was first found in Toulon’s Saint-Musse district, before a second outbreak was identified farther east, in the municipality of Croix-Valmer, in 2024.

A third site was only just discovered in Cavalaire-sur-Mer, also in the Var, in April this year. Under a ministerial order dated 25 March, authorities in the Var have already begun treating the affected areas with powerful insecticides, with some treatments carried out using drones. There is little doubt that the electric ant is moving along the Côte d’Azur, and every indication suggests that control has already been lost.

The electric ant: an invader that lives up to its name

It earned its name because of its sting. Unlike native ants, whose venom is mainly formic acid and burns in a similar way to nettles, its venom is neurotoxic. Although it injects only a minute amount with each sting, the toxin concentration is extremely high, causing intense pain likened to a powerful electric shock. The feeling can last for up to 8 hours, while the resulting itching may continue for as long as 72 hours.

While one sting is not fatal, electric ants often defend themselves collectively, potentially provoking severe allergic reactions in people sensitive to hymenoptera venom, including that of bees, wasps and hornets. In domestic animals such as cats and dogs, repeated stings around the eyes can even cause blindness. Livestock are also at risk, including horses, cattle, sheep and goats.

Beyond the severity of its attacks, this species differs from other pests because of its behaviour. It is known as a tramp ant: it forms interconnected supercolonies containing hundreds or even thousands of queens, which never fight one another. With no competition between them, these colonies can expand with great ease, spreading like oil slicks.

An area infested by a supercolony may contain as many as 20,000 workers per m². At such densities, no other insect species can survive, as the ants effectively clear the ground where they settle, leaving other insects defenceless against them.

What should you do if your home is invaded?

The electric ant is an absolute opportunist: it can settle virtually anywhere and does not need to build an anthill. Leaf litter, dead wood, bark, compost, flowerpots, gaps in house walls and spaces beneath paving slabs can all provide shelter. If it reaches your home, getting rid of it can become a real nightmare.

Treat the ground and they will retreat into the trees; treat the trees in turn and they will hide beneath the terrace, and so on. If you are certain they are on your property, do not waste time trying to eradicate them alone. As this is a listed invasive species, tackling it requires collective action. Report it to your local council - and let your neighbours know too - as well as through official platforms such as the INPN Espèces app, which is available free from the Google Play Store and the App Store. Call in professionals, as only they will have the appropriate bait to kill them.

Climate change could aid the electric ant’s expansion

Given the current situation, it is highly likely that the electric ant will extend even farther across the country and eventually move beyond southern France. It is a highly resilient species that adapts very well to all kinds of environments, although it multiplies especially readily in hot, humid climates. Because of climate change, there is almost no doubt that more northerly metropolitan areas will, within a few years, become habitats just as welcoming to this species as the Var coastline is today.