Another shared feature is that unlike most ant species, army ants do not construct permanent nests, and an army ant colony moves almost incessantly over the time it exists. All species are members of the true ant family Formicidae, but there are several groups that have independently evolved the same basic behavioral and ecological syndrome. This syndrome is often referred to as "legionary behavior", and is an example of convergent evolution.
A 2003 study of thirty species (by Sean Brady of Cornell University) indicates that the ecitonine and doryline army ants together formed a monophyletic group: all shared identical genetic markers that suggest a common ancestor. Brady concluded that these two groups are therefore a single lineage that evolved in the mid-Cretaceous period in Gondwana, and so the two subfamilies are now generally united into a single subfamily Ecitoninae, though this is still not universally recognized (e.g. ).
Accordingly, the army ants as presently recognized consist of the following genera:
Army ant taxonomy remains ever-changing, and genetic analysis will continue to provide more information about the relatedness of the various species.
In the MacGyver episode Trumbo's World (Season 1 Episode 6), MacGyver assists a reclusive landowner in Brazil to defend his home from army ants (referred to in the show as soldier ants). The size of the ant swarm is described as being several miles long and wide. The ants kill several humans in the episode within minutes of being swarmed. They are eventually defeated by flooding the fields on Trumbo's land.
In Indiana Jones and the Kingdom of the Crystal Skull, a legion of siafu eat several Soviet soldiers alive, despite this behaviour not being present in reality. Additionally, Siafu are native to Africa and Asia, and are absent from the film's South American setting (although similar species exist there).
In The Poisonwood Bible by Barbara Kingsolver, a huge swarm of ants attacks the village where the main characters live. The villagers and missionaries all run to the river and escape the ants by boat; they later return to find food and livestock completely devoured, including a memorable description of little piles of chicken bones on the hens' nests. The episode is a decisive moment for the disabled character Adah, because her mother leaves her behind, rescuing her baby sister instead; it is implied that she could have been eaten by the ants.
Personal website on research and computer modeling of army ants (with video and images):
Ant identification made easy: grouping by common traits helps in distinguishing 18 different ant species. (Technical Guide).
Dec 01, 2002; Classifying ants into one of three artificial groups makes their identification a little easier. Group one is composed of ants...