A bivouac is a structure formed by migratory

driver ant ''Dorylus'', also known as driver ants, safari ants, or siafu, is a large genus of army ants found primarily in central and east Africa, although the range also extends to southern Africa and tropical Asia. The term siafu is a loanword from Swa ...

and

army ant The name army ant (or legionary ant or ''marabunta'') is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over a limit ...

colonies, such as the species ''

Eciton burchellii ''Eciton burchellii'' is a species of New World army ant in the genus '' Eciton''. This species performs expansive, organized swarm raids that give it the informal name, ''Eciton'' army ant. This species displays a high degree of worker polymor ...

''. A nest is constructed out of the living ant workers' own bodies to protect the queen and larvae, and is later deconstructed as the ants move on.T. C. Schneirla, Robert Z. Brown and Frances C. Brown (1954) The Bivouac or Temporary Nest as an Adaptive Factor in Certain Terrestrial Species of Army Ants. Ecological Monographs 24(3):269-296 Army ants can forage and feed on insects over large areas of more than 1,800 square yards in a single day, so they must constantly move to new areas. During what is called the migratory phase, the ants set up bivouacs at new sites each night. As many as 150,000 to 700,000 worker bodies cover and protect the queen, linking legs and bodies in a mass that measures a meter across. Thousands of larvae are located near the centre with the queen, and workers are responsible for feeding them. Larger workers also serve as porters, carrying larvae to new bivouacs. In the morning, the bivouac dissolves into raiding columns that form a fan-shaped front. These raiding columns can travel up to 20 metres per hour with lead workers laying a chemical trail for other workers to follow. Smaller workers lead the column, while larger, formidable soldiers protect the flanks.

References

{{reflist Myrmecology Insect behavior