How to Treat for Pest Ants

Locate the nest

The most effective way to manage ants is to locate and directly treat their nest. If possible, follow the feeding trails made by the colony back to their origin. Most ants are nesting outdoors. Once the nest site is located, apply a contact insecticide to the nest to kill the colony.

Use a bait

If the nest cannot be found or the nesting site is inaccessible, use a bait. A bait contains a food attractant combined with a slow-acting insecticide. Workers will feed on the bait and return to the nest to share it with other workers, larvae, and queens to kill the entire colony.

Identify the ant

Before you apply an ant bait, you must first identify the ant species. Ant baits contain a food attractant (sugars, proteins, oils, or a combination) and only work if the ant you are trying to control feeds on it. Food preferences vary among ant species, some are more attracted to sweets and others to fats and oils.

Send in ant samples

Need help with identifying an ant? We can help!

Mail or bring your ant samples to our office (16 E. Lanikaula St., Hilo, HI, 96720). Place ants in a Ziploc bag and freeze for 24 hours to kill them. Please don’t forget to include your contact info!

Primarily bait outdoors

Most ants found indoors are seeking food and water, but will return to nests they have established outdoors. For best use, broadcast baits outdoors over the entire infested area. Only bait indoors if the ants have established a nest indoors. Otherwise, you could attract more ants inside your home. 

Use bait stations indoors

If treating indoors, place bait stations along the trails of the foraging ants to ensure they will find the bait and bring it back to their nest. Be sure to follow the pesticide label’s instructions and only apply baits indoors specifically labeled for use in homes.

Apply a barrier treatment

To prevent ants from entering your home, you can apply a residual barrier treatment around the perimeter of your home to establish a barrier. As ants and other insects crawl over the treated areas, they come into contact with the toxin and are killed. Barrier treatments usually have a residual activity and can provide protection for months.

Seal up entryways

Ant entry into homes can also be reduced by adding caulking or weather stripping around doors, windows, and openings where utility pipes and wires enter from outside.

Remove food sources

Ants enter homes in search of any type of food and water. Make your kitchen as unattractive to ants as possible by keeping your food and rubbish cans tightly sealed, wiping up food particles and sweet liquid residues, and fixing water leaks.

Avoid spraying worker ants

People often make the mistake of using a spray to kill the ants they see walking around their home. If you kill off these ants and forget about the queen hidden in the nest, she’ll continue to lay eggs. Take advantage of the foraging ants in your home and make them work for you by bringing the bait back to the queen.

Trim plants against your house

Trim back shrubbery touching your house and/or tree limbs overhanging your roof that can provide a direct route for ants to make their way inside your home.

Argentine Ants

Scientific name: Linepithema humile

Origins: South America

Description: Argentine Ants are medium to dark brown in color reaching 2-3 mm in length. Widely distributed by human commerce during the early part of the 20th century, they are now found worldwide. It is a common species on all the islands of Hawaiʻi and is usually found at mid-high elevations. At lower elevations, it is out-competed by other ant species. Argentine Ants can form massive colonies. In California, a supercolony spans more than 500 miles. They commonly infest homes and other structures in search of food and water. As omnivores, they feed on nectar, honeydew, and arthropods. They are known to shift food preferences seasonally and depending on colony composition. Considered as one of the most invasive and problematic species of the world, they are a serious ecological pest and can severely disrupt native ecosystems.

Treatment: Argentine Ants usually respond to sugar baits, however, it is recommended to alternate between a sugar bait and a sugar + protein bait for maximum effect. Maxforce Complete might also provide some relief.

Big Headed Ants

Scientific name: Pheidole megacephala

Origins: Africa

Description: Big Headed Ants have two types of workers, major and minor.  This species is named after the disproportionally large head size of the of the major workers often called “soldiers”. The majors are about twice the size (4 mm) of minor workers (2 mm). Body color ranges from light to dark brown. Workers will forage on almost anything including sweet sugary liquids, dead insects, and plant seeds. Colonies generally have multiple queens which can lay hundreds of eggs each day. The transportation of infested materials is known to distribute these ants over long distances, but they can also spread locally via budding and swarming depending on the climate. They can establish themselves practically anywhere from agricultural areas, coastal areas, forests, wetlands, pastures, as well as urban/residential areas. Listed as one of the 100 worst pests in the world, they can also outcompete and displace native invertebrates.

Treatment: Big Headed Ants may be controlled using granular oil baits.

Ghost Ant

Scientific name: Tapinoma melanocephalum

Origins: Unknown. Possibly Africa or Asia

Description: Ghost ants are TINY (~1.5mm) and are recognized by their dark brown head and thorax and light-colored, slightly translucent abdomen and legs. This coloration gives them a “ghostly” appearance making them difficult to spot. They are a prominent tramp species with one of the widest distributions known for any ant species. Colonies can be large and broken into aggregates that occupy different nest sites with multiple queens. They are highly adaptable in their nesting habits, readily nesting in almost any cavity outdoors or indoors. Because of their small size and ability to nest in a variety of materials, they can easily be transported from one location to another. A very common nuisance pest inside homes, workers feed on various household foods but show a preference for sweets. Ghost ants are so small, they can enter containers with loose seals, such as mason jars, plastic food storage bins, and opened bags sealed with “chip clips”. Outside, the workers scavenge for dead insects and collect honeydew from sap-sucking insects.

Treatment: Firstly, cut off the ant’s food supply by wiping up food and spills, sealing pantry food (especially sugary foods) in zipper bags or other tightly sealed containers. Once their food supply is cut off, they can be controlled with sugar baits. Restrict ants entering from outdoors through cracks and crevices with barrier sprays.

Hawaiian Carpenter Ant

Scientific name: Camponotus variegatus

Origins: Southeast Asia

Description: Hawaiian Carpenter Ants are NOT native to Hawaiʻi, but the species was first described on the Hawaiian Islands. They are the largest species of ant in Hawaii, reaching up to 1.27cm in length. Workers are yellowish-brown in color with brown stripes across the abdomen and occasionally along the thorax. Primarily nocturnal in habit, this species is common at low elevations in dry and mesic areas. Workers are polymorphic with three various size casts: minor, media, and major. The smaller minor and media workers care for the brood and queen in the nest while the major workers are tasked with defending the nest and foraging for food. They primarily feed on dead and live insects and honeydew excreted by scales and aphids. In the Fall during mating season, a large number of alates (winged queens and males) will emerge and are easily confused for winged termites. Although it is called the Hawaiian Carpenter Ant, it does not excavate or damage wooden structures like other Carpenter Ant species on the mainland. Instead, it establishes nests in rotting wood and voids hollowed out by termites. Although occasionally these ants will nest indoors in wall voids, hollow doors, and occasionally electronics (e.g. printers, computer monitors, etc.); however, most often they are nesting outside and wandering around inside looking for food.

Treatment: Use of a bait with insect protein food attractant, such as Advance Carpenter Ant Bait or Maxforce Complete, might help control this species indoors. Applying a barrier spray around the house will prevent them from entering the home. 

Longhorned Crazy Ant

Scientific name: Paratrechina longicornis

Origins: Unknown, possibly Africa or Asia

Description: This species is commonly known as the Longhorned Crazy Ant or Black Crazy Ant because of the way they dart around erratically in apparent random directions. Workers are dark brown to black in coloration and 2.3-3mm in length. The long legs and antennae make them easy to distinguish them from other ant species. Longhorn Crazy Ants are the most widespread ant species in the world, because of its ability to successfully thrive in disturbed habitats, live indoors with humans, and easily disperse through human activity. They are highly adaptable, nesting in a variety of locations under debris or in cavities in both dry and moist environments. Workers are opportunistic omnivores often foraging long distances away from their nest. Instead of stinging, they will first bite and then spray formic acid into the wound.

Treatment: Longhorned Crazy Ants can be controlled with sugar baits.

Pharaoh Ant

Scientific name: Monomorium pharaonis

Origins: Unknown. Possibly Africa or Asia,

Description: Pharaoh Ants are yellow to brownish orange ants with darker abdomens, varying in size from 1.5 to 2 mm long. Carried by commerce and trade, Pharaoh Ants have been introduced to virtually every inhabited part of the world. Although they are a tropical species, they also thrive in temperate regions persisting in heated buildings as a major domestic pest. Indoors, they nest in any available small cavities. They are also notorious pests in hospitals where they are potential vectors of disease. Each colony contains multiple queens, allowing them to fragment and quickly invade new areas. They can feed on a variety of foods including sweet, fatty, and oily household foods.

Treatment: Pharaoh Ants may be controlled using granular oil baits.

Singapore Ant

Scientific name: Trichomyrmex destructor

Origins: Unknown, possibly Africa or Asia

Description: Singapore Ants are polymorphic, ranging in size from 1.8 to 3.5 mm. Their bodies are yellow to brownish-orange with a dark abdomen. They will nest in a variety of places but appear unable to establish themselves in undisturbed habitats such as forested areas. They are often found in urban areas as well as irrigated gardens, orchards, and rural areas. These ants spread quickly over long distances through human transportation of infested materials but will spread short distances through budding. They forage on a variety of food sources from dead and live insects to sugary honeydew from plant sucking insects and nectar. This species is most known for its ability to cause costly economic damage by its chewing activity. They will chew holes in plastic, fabrics, and rubber, and even cause fires by chewing on electrical lines. Workers will also enter homes and bite people while sleeping in bed.

Treatment: Singapore Ants may be controlled using granular oil baits.

Tropical Fire Ant

Scientific name: Solenopsis geminata

Origins: North America through Central America

Description: Tropical Fire Ants are orange to brown in color and come in multiple different forms and sizes (3-5mm). Well established in Hawaiʻi since the 1870’s, Tropical Fire Ants are common throughout the islands, most prevalent in dry areas at low elevation. This species prefers to build nests in the soil in open, sunny areas, but does not build large mounds like the Red Imported Fire Ants found in the southeastern part of the United States. As omnivores, they are both insect predators and seed harvesters collecting and storing seeds in granaries within their nests. Tropical Fire Ants also tend honeydew producing Homoptera and girdle young plants to find water. The major workers have a large, square head with large mandibles specialized for milling seeds. If you disturb their nest, workers will swarm and deliver painful stings.

Treatment: Tropical Fire Ants may be controlled using granular oil baits.

White Footed Ant

Scientific name: Technomyrmex albipes, Technomyrmex dificilis, Technomyrmex pallipes, Technomyrmex vitiensis

Origins: Indo-Pacific

Description: White Footed Ants is a common name for four Technomyrmex species which are widely distributed around the world. All four species are similar in appearance and often confused for one or another. These ants are small (2.5-3 mm long) and black in color with distinctive pale-yellow tarsi (feet). They are very common in structures and will nest in almost any location inside and outside of the house. Some of these species can build expansive colonies of up to to 3 million individuals. Because of the enormous size of the colonies, large amounts of food are essential to sustain the populations. They will feed on a wide variety of food sources including sugary substances and dead insects. Unlike many other ant species, White Footed Ants have a unique reproductive structure where there are normal males and queens as well as “ergatoids” (smaller, wingless males and queens that resemble workers), both of which contribute to colony founding and growth. Ergatoids can make up between 15% and 50% of the colony, depending on the species. Also, some of these species do not share food with the rest of the colony. Instead, unfertilized “trophic eggs” are laid and provide food for a large part of the colony. This makes control with baits very difficult because only about half of the colony will feed on the bait and be killed. They do not bite or sting, but are considered a pest primarily due to their sheer numbers. They are also known to tend plant pests such as scale insects, aphids and mealy bugs for the sugary honeydew produced by these insects. This association has contributed to the spread of several serious plant diseases around the world.

Treatment: Most White Footed Ant species are incredibly difficult to control due to the production and feeding on trophic eggs. Sugar baits might provide some knock-down of ant populations, however, it’s better to prevent them from entering the house by using residual barrier treatments.

Yellow Crazy Ant

Scientific name: Anoplolepis gracilipes

Origins: Unknown, possibly Africa or Asia

Description: Yellow Crazy Ants earned their name for their color and erratic behavior when disturbed. They are large (4-5mm), slender ants easily identified by their remarkably long legs and antennae. First reported on Oahu in 1957, they have spread to all the major Hawaiian Islands from sea level to 2,000 ft in elevation. They are often found nesting under leaf litter or in cracks and crevices, and occasionally will nest indoors. Considered to be one of the most destructive invasive ant species in the world, they are considered a major threat to biodiversity. This species may form supercolonies with multiple queens, which can extend over large areas with high densities. Foraging both day and night, Yellow Crazy Ants are “scavenging predators” eating a wide variety of plants and animals dead and alive. Instead of stinging their prey, workers spray formic acid to attack and kill invertebrates and small vertebrates. When introduced to areas with ground nesting birds, they are detrimental to breeding success and chick survivorship. Their diet is also supplemented by nectar and honeydew from insects like scales and aphids.

Treatment: Yellow Crazy Ants usually respond to sugar baits, however, it is recommended to alternate between a sugar bait and a sugar + protein bait for maximum effect. Maxforce Complete might also provide some relief.