Killer Ants (videos)

African driver ants, known locally as Safari ants have the largest colonies of any social insect:

They travel in columns of about twenty million at a time, and will attack anything that cannot get out of their way:

Male driver ants, sometimes known as "sausage flies" are the largest known ants:

via: Spluch: The largest ant in the world

related:
Dorylus - Wikipedia, the free encyclopedia
NPR : The Savage, Beautiful World of Army Ants
BBC - Science & Nature - Articles - Ants can't hurt you, can they?
NOVA | Master of the Killer Ants | PBS