Deep in the Amazon forest lives a small insect with a powerful jaw...
...the leaf-cutter ant.
Its teeth vibrate a thousand times a second
as they slice through these leaves.
The ants don't eat the leaves, they may be toxic,
but they do carry them away.
The path is often dangerous and scary...
...so why do the ants carry all those leaves away?
As their name already suggests, leaf-cutter ants do cut leaves.
The curious thing is, they don't eat the leaves;
they use them to grow something.
But first, they have to haul the gigantic leaf pieces away.
This is no small matter.
For humans, it would be like carrying the equivalent of one ton with their teeth.
More remarkable still, these mini-Hercules range more than 100 meters from their nest.
The human equivalent of a 25-kilometer hike,
Smaller ants ride on the leaf, shot-gun style,
to protect the carrier. from parasitic flies
As they travel, the ants lay down a scent trail to mark the way.
The chemical - a pheromone -
is so powerful that each ant produces only one billionth of a gram.
The ants' nest is huge and may house as many as 8 million individuals.
Here, the leaves are taken to special chambers.
A different class of ant clean the leaves, crush them,
and arrange them carefully.
Afterwards, they spread spores around like seeds and let a fungus grow.
And that - the highly nutritious fungus - that is what the ants are after.
The fungus is their own home-grown food.
Leaf-cutter ants are one of the world's oldest and most competent farmers.
Humans have been farming for about 12,000 years.
These ants have been doing it for 60 million years,
and they don't need shovels or plows.
They use their own bodies.
Their underground cities are vast.
There may be as many as 1000 chambers,
all tended by gardener ants producing fungus for the colony.
All of the ants take their work very seriously,
and they love to optimize their workflow.
If worker ants bring leaves
that contain chemicals that upset its growth,
the fungus somehow tells them, and the ants then gather different leaves.
The Queen is a colossus in this miniature world
and weighs 1500 times more than the small gardener ants.
Only she produces the eggs that will turn into the many different kinds of workers.
The smallest type of ant, the minim,
looks after the queen's eggs and feeds the larvae.
Like human farmers, ants are affected by their environment.
During the wet season, when the rainstorms in the Amazon are so intense
that the forest becomes an amphibious world half-way between air and water,
the leaf-cutter ants are in trouble.
Their pheromone trails are rotting away.
The ants are disoriented.
Their highly organized world is disintegrating under the onslaught
of the rain.
And things are about to get even worse.
There are many hungry predators around,
like this cane toad.
And this amphibian is obviously not interested in vegetarian food.
Besides predators and the torrents of water from above,
the rivers also keep rising, flooding the ants' trails.
Above ground, the insects are severely handicapped by the rains,
but their vast underground colony in the Terra Firme forest
are safe from flooding.
Rain or not, there is always work to do.
The colony is busy growing more fungus, feeding the offspring,
and keeping their house clean.
Leaf-cutter ants are not the only animals with an intricate relationship.
Check out our playlist and follow many more interesting relationships like theirs.