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.