White-footed ant workers are about 1/8inch (3 mm) in length. The body resembles that of the crazy ants. The legs and antennal scape (first long segment) of this species, however, are much shorter. The key identifying character is the pale yellow coloring at the end the legs. This species also resembles the odorous house ant, except for the white-footed ant’s darker color and light colored legs.
This ant is a pest in south Florida in Dade, Broward, and Palm Beach Counties. It also has been found in Naples, Fla., and Sarasota, Fla. It is a pest on Oahu in Hawaii, and established colonies have been found in San Francisco, Calif. It is now an established pest of structures in south Florida, and it may very well be the most difficult structure-infesting ant to control where it occurs. Many pest control experts have literally “thrown up their hands” in surrender when attempting to control this species. The White-footed ant appears to be more of a pest of homes than of commercial buildings, but given time this species should become more widespread in its range and infest all types of structures.
Huge colonies containing several million adults are formed and winged females emerge annually in large numbers from late May to mid June. Colonies that have multiple queens and also contain “intercastes” that have the characters of both queens and workers and which can produce eggs and assist in colony reproduction. The colonies can be huge and eventually contain up to one million individuals. Almost half of the colony consists of workers; the other half is made up of “intercastes” (wingless males and females). Satellite colonies are formed and connect together by foraging trails, creating a large extended colony or “super-colony.” A single extended colony of this ant has been observed to affect numerous adjoining homes, thus confounding control efforts directed at single dwellings.
White-footed ants are particularly fond of sweets and, like many ants, will tend and protect aphids, mealy bugs, and scales that produce “honeydew.” A unique observation is that no oral exchange of food seems to occur among adults of this species. Nutrient transfer occurs via specialized trophic eggs that are produced by all females ( queens, intercastes, and workers). These trophic eggs serve as the food source for the intercasts that do not forage. For this reason, baits prove to be ineffective because only foraging workers may be killed, not the other half of the colony – the queens and intercastes that do not forage.
Outside, trails of White-footed ants will usually be quite visible on walkways, foundations, and the sides of buildings. Once a trail of ants is found, workers carrying bits of food or whose abdomens appear swollen with food or water will usually be returning to the colony. The trail should be followed in the direction in which these workers are heading.
Successful control of White-footed ants depends on the ability to locate foraging ants and nesting sites. White-footed ant colonies living in the soil or under items, such as stones or logs, should be treated by drenching each individual colony with a quality residual insecticide such as Demon WP using a hand held sprayer or backpack sprayer.
White-footed Ant colonies living inside wall voids can be treated by drilling a small hole into the wall and injecting a small amount of a dust insecticide such as Borid Dust. Be sure to use a good duster such as the White Crusader Hand Duster.
If the White-footed ant colony cannot be located, outdoor liquid ant bait stations must be used. Sweet baits such as Gourmet Liquid Ant Bait seem to be preferred by White-footed ants.
Some experts have found that White-footed ants respond better to granular ant baits such as Eclipse Professional Insect Bait if the granulars are ground into finer, smaller particles using a coffee bean grinder.