Army ants typically conjure images of stinging hordes of insects swarming through exotic jungles while villagers flee in terror. Although the truth is less likely to make tabloid headlines, the biology of real army ants is at least as fascinating. Knowledge about these insects has been hard won, as the army ant is no biologist's candidate for a model organism. They are nomadic, unpredictable, largely subterranean, and nearly impossible to culture. That we know anything at all about them is due to the efforts of a small cadre of researchers who revel in difficult field conditions and have the patience to follow meandering trails of ants for months at a time.
Chief among these researchers is Carl Rettenmeyer, professor emeritus at the University of Connecticut, who has tracked army ants through Neotropical rainforests since 1952. Rettenmeyer is known for his pioneering photography of rarely seen aspects of army ants' natural history, his meticulous field observations, and his descriptions of the scores of arthropods that accompany colonies. He was the first to observe, and to photograph, the elusive act of army ant coitus. He was also the first to estimate the longevity of an army ant queen: at least five years, according to a recaptured specimen.
Rettenmeyer has distilled his considerable knowledge into a self-produced film titled Astonishing Army Ants. Any nature film written by a leading, practicing scientist is itself an astonishing find, especially given that most documentaries seem to burst forth, facts-be-damned, from the flashy marketing departments of cable television channels. This film's unique providence renders it a must-see for ant enthusiasts, and I was eager to get my hands on a copy.
The good news: I learned a great deal about army ants. The bad news: the process was exhausting. A career's worth of “astonishing ant facts” cascade in tightly compressed waves for nearly an hour, as if racing against the ant swarms themselves. Narrator Mark Roy, who does an otherwise admirable job, is dragged back and forth by a stream-of-consciousness script with too much information and too little structure. As the film accelerates from scene to scene, viewers are sporadically treated to non sequiturs about iguanas, sloths, and peccaries. Some topics appear twice, and others that might have been expected to be in an army ant film appear not at all.
Curiously absent from an educational film about army ants, for example, is a concise definition of the film's subject. Army ants are a single evolutionary lineage with sibling radiations in the old-and new-world tropics, a lineage that combines the traits of nomadism, group foraging, and wingless queens. The more attentive viewers may be able to piece together some of this definition as the film progresses, but such an essential clarification should not be left to the viewer.
The footage Rettenmeyer has compiled over the past 35 years is uniquely valuable.... [He] has an eye for capturing significant behaviors that would escape less knowledgeable documentarians.
The dense script is not without a silver lining. Astonishing Army Ants does manage considerable depth and breadth of subject matter. Viewers learn about foraging strategies, prey defenses, colony emigration, the nomadic cycle, sensory organs, mating, worker castes, division of labor, and colony fission. The star of Rettenmeyer's DVD is the spectacular Eciton burchellii, the most conspicuous army ant in new-world rainforests, but the film also provides welcome counterpoints to E. burchellii by visiting a number of additional species that specialize on different prey using alternate foraging strategies. The film is sprinkled with interesting asides: ants ignore the feet of ant-birds, ants prefer centipedes over millipedes as food, wasps that nest with ferocious Azteca ants avoid army-ant predation.
The footage Rettenmeyer has compiled over the past 35 years is uniquely valuable, which for ant aficionados more than justifies the price. Viewers are treated to shots of prey ants and prey wasps absconding in the face of impending swarms and of male ants being carried in emigration columns, in addition to the first-ever live footage of grotesquely swollen queens laying eggs. The quality of the cinematography is modest by current standards—much of it appears to have been captured with handheld video cameras—but the charisma of the ants radiates through. Rettenmeyer has an eye for capturing significant behaviors that would escape less knowledgeable documentarians.
Astonishing Army Ants is most engaging when the myrmecologists them selves make an appearance, humanizing the process of discovery: graduate students are wrapped in protective plastic to keep the ants' stings at bay, field assistants lay down string as they track a colony through the dense undergrowth, and in one scene, Rettenmeyer himself delicately marks Eciton queens under a microscope to study their movements. In the film's most memorable moment, a series of furious soldier ants are placed along an unfortunate volunteer's finger, and their fish-hook jaws sink into the skin to demonstrate how indigenous cultures used these ants as living sutures.
However refreshing this documentary may be, Rettenmeyer's project would have benefited from the input of more seasoned filmmakers. The mere presentation of information does not guarantee that a viewer will retain it. A film must also have appropriate pacing and a consistent, logical flow to be an effective educational tool. Astonishing Army Ants is more an archive of accumulated knowledge set to video footage than an enlightening tour for the uninitiated. It will appeal to those who are already enamored of ants, but the narrative is too erratic and too dense for general classroom use.