Deep Dive: What happens when ants invade?

The ants dominate my day-to-day work at the moment.

They've pretty much taken over.

I even dream about ants.

It's almost impossible not to.

Gregor Koschate is the environment officer in Kehl.

Kehl is a town on the Rhine River in southern Germany,

right next to the French border.

And lately it's been getting national media attention because of an exploding population of ants.

This is the famous distribution box that was featured in the news many times.

This is where the ants actually caused the internet outages.

These boxes are not insect-proof.

And the ants built a nest in there, which ended up causing a short circuit.

Several properties in this part of Kiel have had internet and power outages.

The ants have also borrowed under sidewalks and paving stones.

They've built nests in kids' playgrounds and entered some homes and gardens en masse,

moving in dense, black clumps and multi-lane ant highways.

Gregor says he's never seen anything like it before.

I just couldn't believe it.

Seeing hundreds of animals swarming out of such a nest within two to three seconds

and turning a huge area black, it's really alarming.

The ant species in question is Tapinoma magnum.

Grieger estimates that in this part of Kiel there are several million of the ants

and they've colonized an area of up to four hectares, almost eight foot long.

It's certainly a psychological burden for the people here.

It affects their homes and property and they feel kind of helpless because there's nothing they can do about it.

Ants have been around for a lot longer than humans.

Since the Jurassic period, they're found all over the world, on every continent, except Antarctica.

They can live in soil, in trees, below ground, in leaf matter, in deserts and in cities.

Ants may be tiny, but they play a huge role in our world.

They're a crucial part of healthy ecosystems.

But like the Tapinoma magnum, they can also wreak havoc when they end up in new habitats.

This is the dark side of ants, I guess, is that they are amongst some of the worst invasive species.

I'm Neil King.

On this episode of Living Planet, we'll go inside the amazing world of ants.

The dark side, the light…

Ants have fascinated people for a long time.

Ants are cool.

…and the downright weird.

As diverse and crazy as mammals of the Serengeti, just all these wild and crazy looking things.

Hunting ants isn't quite what Gregor imagined he'd be doing

when he started the environment officer job in Kiel back in February last year.

He was supposed to be working on plans to restore habitats and wildlife corridors,

to protect vulnerable species, like an endangered butterfly native to these parts.

But all that has had to take a back seat.

The ants dominate his everyday work now.

He's essentially the one leading the town's fight against the ant problem.

But where on earth to begin?

He hadn't even heard of tapenoma macularis.