Invasive ants are a diverse group of aggressive, competitive, dominating ant species that can rapidly establish and spread. Several ant species are amongst the most serious global invasive species. Their broad diets, nesting habits, ability to breed rapidly, high densitites and adaptibility to varied habitats make them excellent invaders. Agricultural economic, environmental and social wellbeing are threatened by these ants, many of which have been introduced to, and established in, many countries

We conducted ant surveys on Santa Cruz Island, the largest of the California Channel Islands, in 1975/6, 1984, 1993 and 1998. Our surveys yielded a combined total of 34 different ant species: Brachymyrmex cf. depilis, Camponotus anthrax, C. clarithorax, C. hyatti, C. semitestaceus, C. vicinus, C. sp. near vicinus, C. yogi, Cardiocondyla ectopia, Crematogaster californica, C. hespera, C. marioni, C. mormonum, Dorymyrmex bicolor, D. insanus (s.l.), Formica lasioides, F. moki, Hypoponera opacior, Leptothorax andrei, L.