Hairy-headed Leafcutter Ant

Atta cephalotes

"Atta cephalotes" is one of 41 species of leafcutter ant. This species is part of the Attini tribe. A single colony of ants can contain up to 5 million members, and each colony has one queen that can live more than 15 years. The colony comprises different castes, known as ‘task partitioning’, and each caste has a different job to do.
Hairy-headed Leafcutter Ant (Atta cephalotes) This individual is a soldier ant whose task it is to protect a constant stream of foraging workers as they carry leaf material back to the nest. 

It would appear logical to think they eat the leaves,when in fact, they are unable to do so.

Discover what happens to all those leaves by watching this video and reading the accompanying commentary, which includes for me, THE most remarkable fact ever about ants! 

Now there's something to live up to!

https://www.youtube.com/watch?v=S_WuLdurf8s
 Atta cephalotes,Costa Rica,Geotagged,Winter

Behavior

Ants are split into different castes. Soldiers are the largest of the ants and they often stand guard at the entrance of the nest, or will even go on scouting missions to watch for predators. Workers, who are all female, are divided into two types, media and minima, that both have big jaws and sharp teeth. Media workers are the larger of the two, and they cut the leaves and bring them back to the nest. These ants are able to navigate to the source of leaves by following the pheromone scent of the other ants ahead, a process known as ‘tandem running’. Once the media workers have deposited the material into the nest, slightly smaller workers called ‘minima workers’ cut up the leaves into small pieces and then feed it to a fungus they cultivate. They also cover the leaf in antibacterial saliva which stops other types of fungus growing.

A special caste of workers manage the colony's rubbish dump. These ants are excluded from the rest of the colony. If any wander outside the dump, the other ants will kill or force them back. Rubbish workers are often contaminated with disease and toxins, and live only half as long as their peers.

The smaller ‘minima’ workers feed the entire colony of ants. These minima workers also act as guards and follow the media workers or hitch a ride on the leaf they’re carrying to the source of the leaves and attack small parasitoids called phroid flies.

The queen is larger than the other females and is winged. Her role is to give birth to workers.

The females can be workers or soldiers, and cannot produce workers but instead produce males only.

Males are also winged, and their only role is to inseminate the virgin queen.

The leaves that the worker ants cut are not for their consumption, as it is toxic to ants. Instead, the minima ants feeding it to a fungus that they farm.
ant_at_work Leaf cutter ants Atta cephalotes,Geotagged,United Kingdom,Winter

Habitat

Across the rainforest floor they occupy an area typically an area of approximately 20 feet. They live in nests that can be as deep as 7 metres that they have carefully positioned so that a breeze can rid the nest of the dangerous levels of CO2 given off by the fungus they farm and eat.
Atta cephalotes another one of the mountain leafcutters. this photo works well for ID as you can check the head and count the spines. Atta cephalotes,Costa Rica,Geotagged,Winter,ant,atta,leaf cutter

Evolution

Leaf-cutter ants are an extremely specialised species. It has evolved over 25 million years to have a symbiotic relationship with the fungus it farms.

References:

Some text fragments are auto parsed from Wikipedia.

Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassInsecta
OrderHymenoptera
FamilyFormicidae
GenusAtta
SpeciesA. cephalotes