Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Monomorium pharaonis
(pharaoh ant)



Monomorium pharaonis (pharaoh ant)


  • Last modified
  • 16 November 2021
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Natural Enemy
  • Preferred Scientific Name
  • Monomorium pharaonis
  • Preferred Common Name
  • pharaoh ant
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Arthropoda
  •       Subphylum: Uniramia
  •         Class: Insecta
  • Summary of Invasiveness
  • Monomorium pharaonis the pharaoh ant) is native to Africa and has successfully invaded areas on every continent except Antarctica. It is concentrated in tropical regions but is also commonly found in temperate zones within suitable human in...

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report


Top of page
Monomorium pharaonis (pharaoh ant); adult. Ukumehame, Maui. February 20, 2001.
CaptionMonomorium pharaonis (pharaoh ant); adult. Ukumehame, Maui. February 20, 2001.
Copyright©Forest & Kim Starr-2001 - CC-BY-3.0
Monomorium pharaonis (pharaoh ant); adult. Ukumehame, Maui. February 20, 2001.
AdultMonomorium pharaonis (pharaoh ant); adult. Ukumehame, Maui. February 20, 2001.©Forest & Kim Starr-2001 - CC-BY-3.0


Top of page

Preferred Scientific Name

  • Monomorium pharaonis (Linnaeus, 1758)

Preferred Common Name

  • pharaoh ant

Other Scientific Names

  • Atta minuta Jerdon
  • Diplorhoptrum domesticum (Shuckard)
  • Formica antiguensis Fabricius
  • Formica pharaonis Linnaeus
  • Monomorium domestica (Shuckard)
  • Monomorium pharaonis (Linnaeus)
  • Monomorium vastator (Smith)
  • Myrmica (Monomorium) contigua Smith
  • Myrmica (Monomorium) fragilis Smith
  • Myrmica (Monomorium) vastator Smith
  • Myrmica (Myrmecina) domestica Shuckard
  • Myrmica fragilis Smith
  • Myrmica pharaonis (Linnaeus)
  • Myrmica unifasciata Bostock
  • Myrmica vastator Smith

International Common Names

  • English: ant, Egyptian red; ant, little red; pharaoh, ant
  • Spanish: hormiga cosechadora
  • French: fourmi moissonneuse; fourmi pharaon

Local Common Names

  • Denmark: faraomyre
  • Germany: Ameise, Ernte-; Ameise, Knoten-; Ameise, Pharao-
  • Italy: Formica radunasemi
  • Netherlands: Pharaomier
  • Norway: faraomaur
  • Sweden: faraomyra

EPPO code

  • MONOPH (Monomorium pharaonis)

Summary of Invasiveness

Top of page

Monomorium pharaonis the pharaoh ant) is native to Africa and has successfully invaded areas on every continent except Antarctica. It is concentrated in tropical regions but is also commonly found in temperate zones within suitable human infrastructure, especially buildings associated with the distribution or storage of food. Due to Monomorium pharaonis' ability to act as a vector for some bacterial human pathogens, its presence in hospitals is of great concern as it may increase infection rates.

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Arthropoda
  •             Subphylum: Uniramia
  •                 Class: Insecta
  •                     Order: Hymenoptera
  •                         Family: Formicidae
  •                             Genus: Monomorium
  •                                 Species: Monomorium pharaonis

Notes on Taxonomy and Nomenclature

Top of page

Apparently the name "pharaoh ant" originated from Linnaeus' mistaken impression that these ants were one of the biblical plagues during the time of Egyptian pharoahs (Riley 1889, in Ebeling 1996).


Top of page

Workers of the pharaoh ants (Monomorium pharaonis) are approximately 2mm in length and have body colours ranging from light-brown to red. The males are the same size as the workers but are black in colour. The queens are 4mm in length and slightly darker than the workers (Nickerson and Harris 2003).

Please click on AntWeb: Monomorium pharaonis for more images and assistance with identification. The AntWeb image comparison tool lets you compare images of ants at the subfamily, genus, species or specimen level. You may also specify which types of images you would like to compare: head, profile, dorsal, or label.
Please see PaDIL (Pests and Diseases Image Library) Species Content Page Ants: Pharaoh ant for high quality diagnostic and overview images.

Please follow this link for the information sheet on Monomorium pharaonis prepared as part of 'The invasive ant risk assessment project', Harris et al. 2005., for Biosecurity New Zealand by Landcare Research.

Please follow this link for a fully illustrated Lucid key to common invasive ants [Hymenoptera: Formicidae] of the Pacific Island region [requires the most recent version of Java installed]. The factsheet on Monomorium pharaonis contains an overview, diagnostic features, comparision charts, images, nomenclature and links. (Sarnat, 2008).


Top of page

Native range: The pharaoh ant (Monomorium pharaonis) is native to West Africa.
Introduced range: It has been introduced into Asia (including Japan, India and Saudi Arabia), Australia, Europe, and North, Central and South America. It has been introduced onto some islands in the Indian Ocean (including Madagascar) and the Pacific Ocean (including New Zealand and some islands in the Hawaiian and Galapagos archipelagoes) (McGlynn 1999).

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 10 Feb 2022
Continent/Country/Region Distribution Last Reported Origin First Reported Invasive Reference Notes


Central African RepublicPresent


JapanPresentIntroducedInvasiveFirst reported: 1920s
Saudi ArabiaPresentIntroduced


Union of Soviet Socialist RepublicsPresent
GermanyPresentIntroducedFirst reported: <1900
PortugalPresentPresent based on regional distribution.
SpainPresentPresent based on regional distribution.
-Canary IslandsPresentIntroduced
United KingdomPresent

North America

Costa RicaPresentIntroduced
Trinidad and TobagoPresent
United StatesPresent


New ZealandPresentIntroduced1941

South America

-Sao PauloPresent
EcuadorPresentPresent based on regional distribution.
-Galapagos IslandsPresent


Top of page

Many introduced ants, including Monomorium spp., are restricted to a tropical or subtropical climates. The pharaoh ant (Monomorium pharaonis) is not known to invade regions with cold climates although it may be associated with human infrastructure, including climate-controlled buildings. Although its abundance in cold climates will be restricted, its continued presence represents a potential to spread to locations more suitable for ant colonisation (McGlynn 1999; Holway et al. 2002).

Nests are rarely found outdoors but can be found almost anywhere indoors (including light sockets, potted plants and wall cracks or crevices). They typically nest close to sources of warmth and water and many investigators have noted this tendency (Mallis 1969, in Ebeling 1996).

The effect of climatic and temperature variables on ant abundance have been suggested as important when planning eradication programmes in cold to temperate regions. In laboratory conditions the time needed to eradicate pharaoh ant populations depended on the temperature; at 26°C eradication took 3 weeks; at 8°C an eradication could take only 30 minutes (Berndt 1980). Temperatures near 0°C lead to the eradication of large colonies within 6 days, which lead the author to the suggestion that the cold temperatures of the European winter could be exploited for aiding eradications of the pharaoh ant.

Habitat List

Top of page
Terrestrial ManagedDisturbed areas Present, no further details
Terrestrial ManagedUrban / peri-urban areas Present, no further details

Host Animals

Top of page
Animal nameContextLife stageSystem
Psammotermes hybostoma

Host Plants and Other Plants Affected

Top of page
Plant nameFamilyContextReferences
Pinus (pines)PinaceaeUnknown

Biology and Ecology

Top of page

Pharaoh ants (Monomorium pharaonis) are primarily nocturnal, feeding on a variety of foods, including fats, proteins, carbohydrates and small insects. Pharaoh ants will recruit to a number of household foods, including sweets, honey, cakes, greasy foods (such as butter) and fatty foods (such as meats) (Antonelli and Akre 2003).
In laboratory trials Haack and colleagues (1995) investigated the comparative recruitment to and distribution (among workers and larvae) of protein, lipid and carbohydrate. The results were as follows:
A) Recruitment: Liquid carbohydrate was recruited too quickly, while solid carbohydrate (table sugar) was not actively recruited. Corn starch was ignored by foraging workers. Workers actively recruited to sucrose solution and solid protein (moist egg yolk powder) foods after two days of starvation, but a seven day period of starvation was necessary for active recruitment to lipids such as peanut oil (indicating that lipids may not be rapidly depleted in the metabolism of the pharaoh ant).
B) Distribution: Peanut oil and sucrose solution baits were rapidly distributed among adult workers. Peanut oil was distributed rapidly to all larval stages, while the sucrose solution and solid protein baits were distributed primarily to older larvae.

    A queen can lay up to 400 eggs in her lifetime and produces about 10 to 12 eggs per reproductive event. Larval instar development is cyclical at the colony level, suggesting reproductive bursts followed by lower reproductive activity of the queens (Alvares et al. 1993). The species is highly polygynous and workers are sterile. Unlike many ant species, M. pharaonis does not need to leave the nest to mate.

      Lifecycle stages
      A study by Alvares and colleagues (1993) found that total egg to adult development period of the pharaoh ant (Monomorium pharaonis) ranged from 25 days to 54 days (greater than the respective minimum and maximum lengths reported in European populations). Eggs hatch within a week, and the larval period lasts up to 19 days. Queens live for about 12 months and non-sterile males die about 4 weeks after mating. A colony can have a population of several hundred thousand. When overcrowding becomes a problem a queen may take a few workers and immature ants and build a new nest, a mechanism known as budding or colony fission.

        Natural enemies

        Top of page
        Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
        Achaearanea tepidariorum Predator
        Bacillus thuringiensis thuringiensis Pathogen

        Pathway Causes

        Top of page
        CauseNotesLong DistanceLocalReferences
        Horticulture Yes

        Pathway Vectors

        Top of page
        VectorNotesLong DistanceLocalReferences
        Bulk freight or cargo Yes

        Impact Summary

        Top of page
        Human health Negative


        Top of page

        The pharaoh ant (Monomorium pharaonis) is classified as a “generalised Myrmicine” because it has generalised food and nesting requirements and defends resources if they are close to the nest (McGlynn 1999). In addition, M. pharaonis is known as a “tramp” species, which means it is particularly reliant on human-mediated dispersal and has a close association with humans. It frequently nests inside human structures but rarely displaces native species outside urban environments (McGlynn 1999; Holway et al. 2002).

        M. pharaonis is a pest in many populated areas of the world. When it nests in homes, grocery stores or restaurants (which it often does) it often becomes a public nuisance. For example, in the Pacific Northwest it is a nuisance particularly in warehouses, grocery stores and other areas where food is kept (Antonelli and Akre 2003). Its presence in hospitals in of particular concern as it is a vector for the transmission of certain human bacterial pathogens (including Streptococcus pyogenes, Pseudomonas aeruginosa and Staphylococcus epidermidis), which commonly infect hospitalised patients (Nickerson and Harris 2003).

        Please read Invasive ants impacts for a summary of the general impacts of invasive ants, such as their affect on mutualistic relations, the competitive pressure they impose on native ants and the effect they may have on vulnerable ecosystems.

        Risk and Impact Factors

        Top of page
        Impact outcomes
        • Negatively impacts human health
        Impact mechanisms
        • Pest and disease transmission

        Prevention and Control

        Top of page

        Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

        Preventative measures: The Pacific Ant Prevention Programme is a proposal prepared for the Pacific Plant Protection Organisation and Regional Technical Meeting for Plant Protection. This plan aims to prevent the red imported fire ant and other invasive ant species with economic, environmental or social impacts from establishing within or spreading between countries in the Pacific.

        Chemical: In general, ant baits that contain a metabolic inhibitor as the active ingredient (for example hydramethylnon or sulfluramid) have a 2 to 3 day delay before significant mortality occurs, while baits that contain an insect growth regulator (for example methoprene, fenoxycarb or pyriproxyfen) have a delay of several weeks. The latter (IGRs) provide gradual long-term control, while metabolic inhibitors provide short-term, localised and rapid control. As the colonies of pharaoh ant are usually composed of several nest sites a bait containing a metabolic inhibitor (or another fast-acting toxin) may need to be placed at a greater number of sites over a wider area to compensate for the relatively low level of natural toxin spread between the workers (Oi Vail and Williams 2000).


        Top of page

        Alvares, L.E., Bueno, O.C., Fowler, H.G. 1993. Larval instars and immature development of a Brazilian population of pharaoh's ant, Monomorium pharaonis (L.) (Hym., Formicidae) [Abstract], Journal of Applied Entomology 116(1): 90-93.

        Andersen, A. N., J. C. Z. Woinarski, and B. D. Hoffmann. 2004. Biogeography of the ant fauna of the Tiwi Islands, in northern Australia's monsoonal tropics. Australian Journal of Zoology, 52:97-110.

        Antonelli, A.L. and Akre, R.D. 2003. EB1514E Pharoah ant. Washington State University.

        AntWeb, 2006. Monomorium pharaonis

        Berndt, K.P. 1980. Cold tolerance of the Pharaoh's ants (Monomorium pharaonis) [Abstract], Angew Parasitol. 21(3): 164-172.

        Chong, A.C., Cong, N.L., Yap, H.H. and Lee, C.Y. 2002. Effects of Starvation on Nutrient Distribution in the Pharaoh Ant, Monomorium pharaonis (Hymenoptera: Formicidae) Workers and Various Larval Stages, Internat. Conf. on Urban Pests: 121-128.

        Ebeling, W. 1996. Chapter 6: Pests On or Near Food, In: Urban Entomolgy Entomology UC Riverside. University of California (Division of Agricultural Sciences).

        Edwards, J.P. and Abraham, L. 1990. Changes in food selection by workers of the pharaoh's ant [Abstract], Monomorium pharaonis, Med Vet Entomol. 4(2): 205-211.

        Haack, K.D., Vinson, S.B., Olson, J.K. 1995. Food distribution and storage in colonies of Monomorium pharaonis (L.) (Hymenoptera: Formicidae), Journal of Entomological Science 30(1): 70-81.

        Harris, R.; Abbott, K.; Barton, K.; Berry, J.; Don, W.; Gunawardana, D.; Lester, P.; Rees, J.; Stanley, M.; Sutherland, A.; Toft, R. 2005: Invasive ant pest risk assessment project for Biosecurity New Zealand. Series of unpublished Landcare Research contract reports to Biosecurity New Zealand. BAH/35/2004-1.

        Hoffmann, B. 2004. Exotic ants threaten indigenous lands, Australasian Science 25 (6).

        Holway, D. A., L. Lach, A. V. Suarez, N. D. Tsutsui, and T. J. Case. 2002. The ecological causes and consequences of ant invasions. Annual review of ecology and systematics 33:181-233.

        Hooper-Bui, L.M., Appel, A.G. and Rust, M.K. 2002. Preference of food particle size among several urban ant species [Abstract], J Econ Entomol. 95(6): 1222-1228.

        Klunker, R., Rupes, V. and J., Chmela. 1984. Control of Monomorium pharaonis using a methoprene bait in the Berlin Zoo and its combined application with a residue insecticide in the Olomouc Children's Clinic [Abstract], Angew Parasitol. 25(2): 83-93.

        Krzeminska, A., Sawicka, B., Gliniewicz, A. and Kanclerski, K. 1997. Preliminary evaluation of the incidence and control of insects: Pest control in Polish hospitals [Abstract], Rocz Panstw Zakl Hig. 48(3): 295-303.

        Longino, J.T. 2003. Evergreen State University. Monomorium pharaonis (Linnaeus 1758).

        McGlynn, T.P. 1999. The Worldwide Transfer of Ants: Geographical Distribution and Ecological Invasions, Journal of Biogeography 26(3): 535-548.

        Ness, J.H and Bronstein, J.L. 2004. The Effects of Invasive Ants on Prospective ant Mutualists, Biological Invasions 6: 445-461.

        Nickerson, J.C. and Harris, D.L. 2003. Featured Creatures. Florida Department of Agriculture and Consumer Services (Division of Plant Industry).

        Ogata, K. and Terayama, M. 2003. Monomorium pharaonis. Japanese Ant Image Database.

        Oi, D.H., Vail, K.M. and Williams, D.F. 2000. Bait distribution among multiple colonies of Pharaoh ants (Hymenoptera: Formicidae), Journal of Economic Entomology 93(4): 1247–1255.

        Pacific Ant Prevention Programme, March 2004. Pacific Invasive Ant Group (PIAG) on behalf of the IUCN/SSC Invasive Species Specialist Group (ISSG).

        Rupes, V., Chmela, J. and Ledvinka, J. 1997. Comparison of the efficacy of baits with sulfluramid, hydramethylnon and methoprene against Pharaoh's ant [Abstract], International Pest Control 39(6): 189-191.

        Sarnat, E. M. (December 4, 2008) PIAkey: Identification guide to ants of the Pacific Islands, Edition 2.0, Lucid v. 3.4. USDA/APHIS/PPQ Center for Plant Health Science and Technology and University of California — Davis.

        Schedl, W. 1993. The occurrence of pharaoh ants in Tyrol (Austria) [Abstract], Berichte des Naturwissenschaftlich-Medizinischen Vereins in Innsbruck 80(0): 359-361.

        Slotterback, J.W., Oboyski, P.T. and Banko, P.C. 2001.Ant invasions of mamane-naio forest at high elevations on Mauna Kea. USGS.

        Stanley, M. C. 2004. Review of the efficacy of baits used for ant control and eradication. Landcare Research Contract Report: LC0405/044. Prepared for: Ministry of Agriculture and Forestry.

        Vail, K.M. and Williams, D.F. 1995. Pharaoh ant (Hymenoptera: Formicidae) colony development after consumption of pyriproxyfen baits [Abstract], J Econ Entomol. 88(6): 1695-1702.

        Varnham, K. 2006. Non-native species in UK Overseas Territories: a review. JNCC Report 372. Peterborough: United Kingdom.

        Walker, K. 2006. Pharaoh ant (Monomorium pharaonis) Pest and Diseases Image Library. Updated on 29/08/2006 12:04:04 PM.

        Wetterer, J. K. 2002. Ants of Tonga (1). (Statistical Data Included).Pacific Science, April 2002 v56 i2 p125(11).

        Wetterer, J.K., Banko, P.C., Laniawe, L.P., Slotterback, J.W. and Brenner, G.J. 1998. Nonindigenous ants at high elevations on Mauna Kea, Hawai'i [Abstract], Pacific Science 52(3): 228-236.


        Top of page

        Badr, S. A., 2014. Insects and non insects species associated with pine needle trees in Alexandria Egypt. Journal of Entomology, 11(1), 49-55.

        ISSG, 2011. Global Invasive Species Database (GISD). Invasive Species Specialist Group of the IUCN Species Survival Commission.

        Distribution References

        Badr S A, 2014. Insects and non insects species associated with pine needle trees in Alexandria Egypt. Journal of Entomology. 11 (1), 49-55.

        CABI Data Mining, 2001. CAB Abstracts Data Mining.,

        CABI Data Mining, Undated. CAB Abstracts Data Mining.,

        CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

        CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

        Invasive Species Specialist Group (ISSG), 2011. Global Invasive Species Database (GISD). In: Global Invasive Species Database (GISD), Auckland, New Zealand: University of Auckland.

        Seebens H, Blackburn T M, Dyer E E, Genovesi P, Hulme P E, Jeschke J M, Pagad S, Pyšek P, Winter M, Arianoutsou M, Bacher S, Blasius B, Brundu G, Capinha C, Celesti-Grapow L, Dawson W, Dullinger S, Fuentes N, Jäger H, Kartesz J, Kenis M, Kreft H, Kühn I, Lenzner B, Liebhold A, Mosena A (et al), 2017. No saturation in the accumulation of alien species worldwide. Nature Communications. 8 (2), 14435.


        Top of page

          Compiled by: IUCN SSC Invasive Species Specialist Group Updates with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment

          Last Modified: Monday, October 04, 2010

        Distribution Maps

        Top of page
        You can pan and zoom the map
        Save map
        Select a dataset
        Map Legends
        • CABI Summary Records
        Map Filters
        Third party data sources: