Argentine Ants

Habits

Argentine ants are very efficient foragers that follow regular trails when searching for food, and winged queens can sometimes be found among trailing workers. Unlike most ants, who only deposit pheromone trails on their way back to the nest from a food source, Argentine ants will deposit pheromone trails both to and from a food source. This behavior ensures they do not waste time revisiting the same area for food. Their preferred foods are sucrose-containing sweets, but they increase their intake of protein-rich foods during their peak reproductive months of the spring and summer. Argentine ants are known to be aggressive towards other ant species, and will attack competing ants when they move into a new area.

Argentine ant queens mate with males solely to populate the colony. Mating is the only purpose for Argentine ant males who will live for about a year and then die shortly after mating. The eggs laid by queens usually produce sterile female workers, who have many responsibilities in the colony including foraging for food, nursing eggs and feeding larvae.

Argentine ant colonies can contain hundreds of queens. For every 1,000 worker ants, it’s estimated there can be up to 15 queens. Unlike some other ant species that establish new nests through swarming, Argentine ants reproduce through a process known as budding where queens and males will mate within the parent nest before leaving with a handful of workers to start a new nest. These networks of interconnected nests can expand to form massive colonies called supercolonies that can contain millions of members, including multiple queens, and have been known to populate entire city blocks.

Habitat

Argentine ant colonies are typically located in wet environments near a food source. Outdoors, they usually build shallow nests in moist locations such as under boards or stones, beneath plants or along sidewalks. When the conditions outside are not favorable for the ants to thrive, usually too cold or too dry, Argentine ants have been known to invade buildings in large numbers. Once inside, they will still nest near a source of moisture, such as water pipes, sinks and potted plants. One common way ants gain entry into a home is by trailing along tree branches or utility lines that contact the structure.

Threats

Argentine ants do not pose an extreme health threat, but they are known to crawl over sewage, trash and dead animals while looking for food and can be carriers of disease-causing bacteria for conditions like dysentery. If they gain access to a household’s kitchen, they are capable of contaminating food. In areas where large numbers of Argentine ants are present, workers have even been known to attack poultry chicks and destroy beehives.