of millions of individuals that descend from a single queen. These three traits are found in all army ant species and are the defining traits of army ants. Nomadic and stationary phase Army ants have two phases of activitya nomadic (wandering) phase and a stationary (statary) phasethat constantly cycle, and can be found throughout all army ant species. The nomadic phase begins around 10 days after the queen lays her eggs. This phase will last approximately 15 days to let the larvae develop. The ants move during the day, capturing insects, spiders, and small vertebrates to feed their brood. At dusk, they will form their nests or bivouac, which they change almost daily. At the end of the nomadic phase, the larvae will spin pupal cases and no longer require food. The colony can then live in the same bivouac site for around 20 days, foraging only on approximately two-thirds of these days. Among the army ants are some species that venture out only at night, but no adequate studies of their activities have been made. The stationary phase, which lasts about two to three weeks, begins when the larvae pupate. From this point on, the prey that were previously fed to the larvae are now fed exclusively to the queen. The abdomen (gaster) of the queen swells significantly, and she lays her eggs. At the end of the stationary phase, both the pupae emerge from their cocoons (eclosion) and the next generation of eggs hatch so the colony has a new group of workers and larvae. After this, the ants resume the nomadic phase. Colony fission Army ants will split into groups when the size of the colony has reached a size threshold, which happens approximately every three years. Wingless virgin queens will hatch among a male sexual brood that hatches at a later date. When the colony fissions, there are two ways new queens are decided. A possible outcome is a new queen will stay at the original nest with a portion of the workers and the male brood while the old queen will leave with the rest of the workers and find a new nest. Another possibility is that the workers will reject the old queen and new queens will each head a newly-divided colony. The workers will affiliate with individual queens based on the pheromone cues that are unique to each queen. When new bivouacs are