Encyclopedia of Social Insects

Living Edition
| Editors: Christopher K. Starr

Bullet Ant (Paraponera clavata)

  • Michael D. BreedEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-90306-4_67-1


Giant tropical ant

Paraponera clavata is a common and conspicuous inhabitant of lowland moist and wet habitats in much of the neotropics. It is commonly known as the bullet ant because of its very painful sting, or the giant tropical ant because of its large size, up to 2.5 cm in length. It is also noteworthy on account of its taxonomic position. Its behavior and ecological relations have been relatively well studied, providing a window into the adaptive tools available to ants as they evolve.

P. clavata is the single known member of the subfamily Paraponerinae [11]. For many years, based on superficial similarities, it was placed in the Ectatomminae, where it was thought to be most closely related to the genera Ectatomma and Rhytidoponera. Molecular studies have since revealed a substantial distance between Paraponera and the ectatommines, with Paraponera closer to the subfamily Ponerinae and the Ectatomminae closer to the Myrmicinae. This distinction is important, because many of the earlier publications on Paraponera characterize it as primitive and look to build insights into the evolution of social mechanisms in ants by considering Paraponera and Ectatomma365体育网站 as part of a closely knit evolutionary sequence. Present-day understanding is that these arguments were based on false phylogenetic assumptions.

Distribution and Nests

Paraponera365体育网站 is found only in the neotropics from Bolivia in the south to northern Central America and spanning nearly the entire breadth of South America east of the Andes. Within this range, it is most common at low to mid-elevations (1000 m and below) in habitats with more than 1.5 m of rain distributed relatively evenly through the year. While common in undisturbed forest habitats, it is also found in secondary forest.

Paraponera nests are typically found in the soil at the base of large trees, but much of the foraging activity is in the forest canopy. Each colony is founded by a single queen and can grow to contain up to 2000–3000 workers. In two forests in which nest distribution was mapped – Barro Colorado Island in Panama and La Selva Biological Station in Costa Rica – nests were regularly spaced at roughly 20-m intervals. This even distribution suggests territoriality, and in fact lethal combat among workers from different colonies is often observed [5].


Foraging workers vary somewhat in size, but all foragers are at the larger end of this species’s size range [3]. The largest workers participate in defending the colony against major disturbances. Smaller workers, rarely seen outside the nest, apparently participate in brood care. This pattern of large, unimodal size variation amongworkers, coupled with size-specific task specialization, is common but certainly not universal in ants. Workers display some allometry, with larger workers having disproportionately large heads.


Paraponera collects mostly floral and extrafloral nectar (Fig. 1) and insects (Fig. 2) but has also been observed preying on small vertebrates, including frogs. The main trail of a colony extends from the colony entrance up the trunk of the nest tree, where it splits to follow branches into the canopy. Ants exit the nest singly and often forage independently. Paraponera has trail pheromones (Fig. 3), which can be used either by single workers to create guidelines for orientation during foraging or in recruitment to rich food resources. Workers recruit to both sugary (especially nectar) and animal foods, but recruitment responses to animal foods (such as a vertebrate carcass) are much stronger [4, 7, 8, 9]. A stable-isotope study showed that most of the carbon in Paraponera workers is derived from plant sources and that nitrogen source varied substantially among colonies, with some colonies more dependent on prey than others. Paraponera are active predators, seeking prey that they frequently capture and immobilize by stinging.
Fig. 1

A Paraponera clavata365体育网站 worker carrying a droplet of nectar. Note that the large mandibles and setae along their lower create a basket for holding large quantities of liquid. (Photo © Alex Wild)

Fig. 2

Paraponera workers are efficient predators, subduing prey, such as this caterpillar, with their potent sting and strong mandibles

Fig. 3

Paraponera workers communicate about food locations by laying chemical trails. This ant is pressing the tip of her abdomen to the substrate, the characteristic trail-laying posture of this species

Orientation and Navigation

Paraponera workers have strong visual orientation capabilities in addition to their ability to follow pheromone trails [1, 8365体育网站]. They use landmarks in navigation and also visually orient to prey. Much of their foraging activity is at night, particularly during dry seasons, and they have noteworthy skills in visual navigation under conditions with minimal light.

Colony Defense

Given the large biomass of each worker and of the colony as a whole, it is not surprising that Paraponera requires effective defense against predators. Their highly potent venom makes this possibly the world’s most painful stinging insect. The stinger is long (3–4 mm), so that a worker can deliver venom deep into the tissue of a potential predator [10]. Some Amazonian indigenous peoples employ Paraponera stings in male initiation rituals [2]. Additionally, workers are protected chemically by a noxious and highly odorous compound. Few vertebrates attempt to prey on this ant, and insect predators, such as army ants, tend to ignore or avoid Paraponera nests. A phorid fly, Apocephalus paraponerae, orients to the chemical defense of the workers and then parasitizes adults by laying its eggs on them [6].


The bullet ant, Paraponera clavata365体育网站, is among the emblematic species of neotropical rainforests. Remarkable for its size and the intensity of its sting, it is an unusually good study organism, as colonies are easily located and the workers are large enough to make observations of individuals feasible. This species has many of the physiological and behavioral adaptations associated with the ecological success of ants, including recruitment of nestmates to food, size-based behavioral castes, and highly effective colony defenses.


  1. 1.
    Baader, A. P. (1996). The significance of visual landmarks for navigation of the giant tropical ant, Paraponera clavata (Formicidae, Ponerinae). Insectes Sociaux, 43, 435–450.
  2. 2.
    Bosmia, A. N., Tubbs, R. S., Griessenauer, C. J., & Haddad, V. (2015). Ritualistic envenomation by bullet ants among the Satere-Mawe Indians in the Brazilian Amazon. Wilderness & Environmental Medicine, 26, 271–273.
  3. 3.
    Breed, M. D., & Harrison, J. (1988). Caste in the giant tropical ant, Paraponera clavata. Journal of the Kansas Entomological Society, 61, 285–290.
  4. 4.
    Breed, M. D., Fewell, J. H., Moore, A. J., & Williams, K. (1987). Modulated recruitment in a ponerine ant. Behavioral Ecology and Sociobiology, 20, 407–411.
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    Breed, M. D., Stiller, T. M., Fewell, J. F., & Harrison, J. M. (1991). Territoriality and nestmate discrimination in the giant tropical ant. Biotropica, 23, 301–306.
  6. 6.
    Brown, B. V., & Feener, D. H. (1991). Behavior and host location cues of Apocephalus paraponerae (Diptera: Phoridae), a parasitoid of the giant tropical ant, Paraponera clavata (Hymenoptera: Formicidae). Biotropica, 23, 182–187.
  7. 7.
    Fewell, J. H., Harrison, J. F., Lighton, J. R. B., & Breed, M. D. (1996). Foraging energetics in of the ant, Paraponera clavata. Oecologia, 105, 419–427.
  8. 8.
    Harrison, J. F., Fewell, J. H., Stiller, T. M., & Breed, M. D. (1989). Effects of experience on use of orientation cues in the giant tropical ant. Animal Behaviour, 37, 869–871.
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    McGlynn, T. P., & Parra, E. L. (2016). Mechanisms of carbohydrate-fuelled ecological dominance in a tropical rainforest canopy-foraging ant. Ecological Entomology, 41, 226–230.
  10. 10.
    Schmidt, J. O. (2018). Clinical consequences of toxic envenomations by Hymenoptera. Toxicon, 150, 96–104.
  11. 11.
    Ward, P. S. (2014). The phylogeny and evolution of ants. Annual Review of Ecology, Evolution, and Systematics, 45, 23–43.

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Authors and Affiliations

  1. 1.Ecology and Evolutionary BiologyThe University of Colorado, BoulderBoulderUSA