Just about every California resident is surely aware of the indoor ant pest named Linepithema humile, or the “Argentine ant,” as the species is better known. These ants were first discovered in the country when colonies were recovered near the New Orlean’s coast during the 1890s, and they were found in California for the first time in 1907. Argentine ants are easily the most common ant pests that pest control professionals encounter within and around homes in California, and they are particularly common in California’s coastal counties. In fact, one single colony, or “supercolony” of Argentine ants spans 560 miles along the California coast where they invade structures at a constant rate.

A 2005-2006 study found that Argentine ants accounted for 85 percent of the ant species collected by pest control professionals within and around homes in coastal counties in southern California, and today, the ants are even more abundant in the region. Argentine ants are unique for forming enormous colonies that have become known as supercolonies, and they contain millions of workers, hundreds or thousands of queens, and numerous nesting sites that span massive areas of land. Workers are known to forage greater than 350 feet from their nests, and exceptionally large herds of these ants often intrude into neighborhoods where they enter homes in overwhelming numbers.

Within homes, Argentine ants invade pantries and stored foods, and they will eat virtually anything, but they prefer sweets, and high-protein foods, especially egg yolks. These ants also cover yards and the exterior walls of homes where they consume nesting wasps, bees and even baby birds after adult birds flee in terror. These ants require moist environments in order to thrive, which is why large numbers are frequently found on irrigated fields, yards and gardens, and within cupboards below sinks and bathroom wall voids within homes. The brown-colored Argentine ant workers are quite small at 3/16 of an inch in length, and despite their aggressive behavior, they luckily do not sting or bite.

Have you ever struggled to control an Argentine ant infestation?