A world of ants

Ants in arid climates must store food to survive long periods of dearth. In the deserts of North America, Myrmecocystus honeypot ants use their bodies as living containers, their bodies swelling with liquid reserves that they regurgitate to nest mates when needed.

Superorganism in motion: raiding columns of the army ant Eciton burchellii.

Larvae are increasingly seen by ant scientists not just as immature ants but as integral parts of the colony. They help regulate the nutrition of all ants in the colony, and in some species they are even essential for nest construction. The species pictured here, a type of Dracula ant (Adetomyrma) from Madagascar, is one of thousands of undescribed ant species awaiting formal taxonomic recognition.

Unique combinations of paint let ant researchers like Anna Dornhaus of the University of Arizona track the activities of individuals in a nest. Dr. Dornhaus painted these Temnothorax rugatulus ants with model airplane paint.

The Indian jumping ant, Harpegnathos saltator, will be one of the first ants to have its genome sequenced.

A Podomyrma ant tending to a Lycaenid caterpillar in South Australia. These caterpillars secrete substances that the ants find attractive, and the ants in turn provide protection from parasites. Ants are so abundant that many other species have come to depend on them in various ways.

Among the oddities of the ant family are the Malagasy mystery ants (Mystrium species), which are predatory inhabitants of rain forest leaf litter.

Two harvester ants (Pogonomyrmex rugosus) from adjacent nests engaging in ritual warfare, pushing in a display of force but not actually harming each other. It is thought that colonies use these mock battles to gather information about their neighbors. Knowledge about the strength of competing colonies helps ants set territorial borders without loss of life.

Some species subdivide the worker caste into different sizes and shapes, allowing them to tackle a broader range of tasks. Nowhere is this more pronounced than in the Atta leaf-cutting ants. The differences between these two genetically similar nest mates result from nutrition-dependent developmental trajectories.

Cecropia ants (Azteca alfaroi) guard their tree zealously against intruders. Working together, they surround and immobilize their opponents by pinning down their appendages.

One of the world's rarest insects is Thaumatomyrmex, a tropical American ant whose bizarre mandibles had long mystified ant scientists. In 1990, a Brazilian team finally solved the puzzle: Thaumatomyrmex are specialized predators of a porcupine-like millipede. The long jaws allow the ant to grasp its prey without getting injured.

On a Panamanian island, workers of the crazy ant (Paratrechina longicornis) drinking from nectaries on the underside of a leaf. Many plants attract ants with nectaries, and the ants in return help remove the plant's herbivorous pests.

The South American Dinoponera species, at over an inch long, are some of the world's largest ants.

Ants mate in the air. Here, the desert leaf-cutting ant Acromyrmex versicolor during a morning mating flight above Tucson, Ariz.