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)

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).\r\n

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.

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.

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).

Please follow this link for more detailed information on the management of the Argentine ant Linepithema humile compiled by the ISSG.