Ants are one of the most successful groups of insects.

They are social insects that live in colonies which are usually located in the ground, but they may enter buildings for shelter and/or food. Ants feed on practically every kind of food, but those entering homes are looking for sweets and/or protein-containing substances. About 700 species of ants occur in the United States and Canada. Of these, only about 25 species commonly infest homes.

The biology and habits of each ant species are different, so a detailed knowledge of these for each species is necessary for effective control.

  • More than 20 varieties of ants invade homes throughout the United States during the warm months of the year.
  • Worldwide, there are more than 12,000 species, but only a small number cause problems.
  • Destructive ants include fire and carpenter ants. Others ant types include the honey, Pharaoh, house, Argentine, and the thief ant.
  • All ants share one trait: They’re unsightly and contaminate food.
  • Ants range in color from red to black.
  • Fire ants are vicious, unrelenting predators with a powerful, painful sting.
  • At least 32 deaths in the U.S. can be attributed to severe allergic reactions to fire ant stings.
  • Millions of dollars are spent each year eradicating fire ants alone.
  • Carpenter ants range in size from one-quarter inch for a worker ant to up to three-quarters inch for a queen.
  • A carpenter ant colony can have a long life span. Each colony is founded by a single fertilized queen that establishes a nesting site in a cavity in wood.
  • A carpenter ant colony does not reach maturity until it contains 2,000 or more workers, which can take three to six years.

Argentine Ants

Linepithema humile (Mayr)

Argentine-AntsArgentine ants were imported from South America just over a hundred years ago. They are found in the south and west with spotty infestations in northern states.

Argentine ant colonies can grow to monumental size.

Their colony borders sometimes cover entire habitats. Argentine ant queens also assist with foraging for food. The ant gives off a musty odor when crushed. Worker argentine ants are about one sixteenth of an inch long. Queen argentine ants are one eighth of an inch to one quarter of an inch long.

Pest Facts

Color: Dark brown to black; shiny
Legs: Six
Shape: Segmented; oval
Size: 1/16-1/4 inches
Antennae: Yes
Flying: Rare winged swarmers
Region: AL, AR, CA, FL, GA, IL, LA, MD, MO, MS, NC, OR, SC, TN, WA

Habits

Argentine ants deposit trails continuously, instead of just from nest to food source. This habit ensures they do not waste time visiting the same area for food. They prefer to eat sweets but they will eat almost anything including meats, eggs, oils and fats. Argentine ants usually nest near a food and water source. Their food preference is honeydew or similar sweets, but they will feed on protein and fats if necessary. These ants can spread pathogens due to their habit of crawling over any obstacle rather than going around. These ants, if living outside, will invade structures during drought.

Habitat

Argentine ant colonies are located in wet environments near a food source.

Threats

Argentine ants do not pose a health threat, but they can contaminate food.

Eliminate standing water. Pests, such as Argentine ants are attracted to moisture. Keep tree branches and other plants cut back from the house. Sometimes pests use these branches to get into your home. Make sure that there are no cracks or little openings around the bottom of your house. Sometimes pests use these to get into your home. Make sure that firewood and building materials are not stored next to your home. Pests like to build nests in stacks of wood.

Argentine ants can be controlled using non-repellent dusts and baits.

Carpenter Ants

Description

Carpenter-AntsCarpenter ants get their name because they excavate wood in order to build their nests. Their excavation results in smooth tunnels inside the wood (formicarium). Carpenter ants range in size from one-quarter inch for a worker ant to up to three-quarters inch for a queen.

Size ranges from one-fourth inch for a worker ant to up to three-fourths inch for a queen in the most common species. May range from red to black in color. Build nests in deteriorating, moist wood; often the colony will extend its nest into adjacent, sound wood. Are commonly found in porch pillars and roofs, window sills, telephone poles, live and dead trees, rotting logs and stumps and wood in contact with soil. Do not actually eat the wood removed during nest-building activities; rather, deposit it outside entrances to the colony in small piles.

Pest Facts

Color: Varies depending on species, from red to black or a combination. The two most common species are black.
Legs: Six
Shape: Segmented; oval
Size: 5/8 inches
Antennae: Yes
Flying: Winged swarmers
Region: Contiguous states

Habits

All species mainly attack wood that is or has been wet and damaged by mold. Even though these ants first invade wet, decayed wood, they may soon begin building paths through dry, undamaged wood. They usually come into buildings through cracks around doors, windows, or through holes for wires. They will also crawl along overhead wires, shrubs, or tree limbs that touch the building far above the ground.

Habitat

Carpenter ants build their nests outdoors in various wood sources, including tree stumps, firewood or landscaping. They need a constant water source to survive. They will enter homes through wet, damaged wood.

Threats

Carpenter ants damage wood through their nest building. If they gain entry to a structure, they pose a property threat. They can convey a painful bite with pronounced mandibles and injection of formic acid into the wound.

Prevention

Because carpenter ants require a water source, eliminate sources of moisture or standing water. Keep tree branches and other plants cut back from the house. Sometimes pests use these branches to get into your home. Make sure that there are no cracks or little openings around the bottom of your house. Sometimes pests use these to get into your home. Make sure that firewood and building materials are not stored next to your home. Pests like to build nests in stacks of wood.

Fire Ants

Fire ants are found primarily in the southern half of the U.S.

Fire AntsThe fire ant’s bites and stings can be very painful and even fatal. The most common fire ants in the U.S. are the red imported fire ant and the southern fire ant. Fire ant workers are polymorphic, meaning that the workers are not all the same size. The fire ant worker typical size is 1/4” to 1/16”, and the head and thorax are yellowish red with a black abdomen. The coloring is the most distinguishing characteristic. There are two nodes on the pedicel visible with a hand lens. Stingers will be exposed on ants placed in alcohol. Red imported fire ants nest in soil and build mound nests. They can infest garages.

Pest Facts

Color: Dark reddish brown
Legs: Six
Shape: Segmented; oval
Size: 1/8-3/8 inches
Antennae: Yes
Flying: Winged swarmers
Region: Southeastern U.S. from Virginia to Texas

These ants will frequently build mounds, but can be found in excavated areas under slabs. Commonly the excavated soil will be piled up to a foot
high on a slab or in a garage corner. The ants also inhabit the excavated soil. These ants will also infest voids in buildings near soil and will infest electrical meters and boxes, and cable boxes.

Workers forage in trails and prefer proteins but will feed on sweets, vegetation and seeds.

Fire ants are particularly dangerous to children and small animals. In May 2003, a child died in the southwest after being attacked by fire ants.

Prevention

Red imported fire ants and their telltale mound nests should be actively avoided. To prevent entry into a structure, seal all internal and external cracks and crevices.

Baits and residual liquid applications are effective controls.

In a structure, a one-time application of a residual works well. Insect growth regulators are also available and require several applications timed to expose several generations to the IGR.

Odorous Ants

Fire ants are found primarily in the southern half of the U.S.

Fire AntsThe fire ant’s bites and stings can be very painful and even fatal. The most common fire ants in the U.S. are the red imported fire ant and the southern fire ant. Fire ant workers are polymorphic, meaning that the workers are not all the same size. The fire ant worker typical size is 1/4” to 1/16”, and the head and thorax are yellowish red with a black abdomen. The coloring is the most distinguishing characteristic. There are two nodes on the pedicel visible with a hand lens. Stingers will be exposed on ants placed in alcohol. Red imported fire ants nest in soil and build mound nests. They can infest garages.

Pest Facts

Color: Dark reddish brown
Legs: Six
Shape: Segmented; oval
Size: 1/8-3/8 inches
Antennae: Yes
Flying: Winged swarmers
Region: Southeastern U.S. from Virginia to Texas

These ants will frequently build mounds, but can be found in excavated areas under slabs. Commonly the excavated soil will be piled up to a foot
high on a slab or in a garage corner. The ants also inhabit the excavated soil. These ants will also infest voids in buildings near soil and will infest electrical meters and boxes, and cable boxes.

Workers forage in trails and prefer proteins but will feed on sweets, vegetation and seeds.

Fire ants are particularly dangerous to children and small animals. In May 2003, a child died in the southwest after being attacked by fire ants.

Prevention

Red imported fire ants and their telltale mound nests should be actively avoided. To prevent entry into a structure, seal all internal and external cracks and crevices.

Baits and residual liquid applications are effective controls.

In a structure, a one-time application of a residual works well. Insect growth regulators are also available and require several applications timed to expose several generations to the IGR.

Pavement Ants

Description

Pavement-AntsPavement ants get their name because they make their nests in or under cracks in pavement. They can infest structures. Pavement ants are commonly first observed by finding piles of granular excavated soil from between cracks on sidewalks and driveways. Pavement ants are found in the eastern U.S. and on much of the west coast. These ants look similar to odorous house ants but can be distinguished from odorous house ants by a hand lens. The pavement ant has groves on the “face” and has two nodes on the pedicel. These ants are also small, 1/16”-1/8” long, with flying reproductives about three times the length of the workers. Reproductives may emerge any time of the year. The thorax of workers has one pair of spines.

Pest Facts

Color: Dark brown to blackish
Legs: Six
Shape: Segmented; oval
Size: 1/8 inches
Antennae: Yes
Flying: Winged swarmers
Region: All 50

Habits

Habits of pavement ants are similar to those of odorous house ants, although pavement ants are opportunistic feeders. These ants will eat insects, honeydew and sweets, but prefer protein and fats. These ants will eat almost anything, including insects, seeds, honeydew, honey, bread, meats, nuts and cheese. If pavement ants invade a structure, they usually prefer food spills found near easy access to pathways back to nesting sites. Inspection of entry points should include foundations and weep holes in brick veneer.

Habitat

These ants live in or under pavement cracks.

Threats

These ants do not pose a public health risk, but they can contaminate food and should be avoided. They are not aggressive, but can bite and sting.

Prevention

Eliminate standing water. Pests, such as ants, are attracted to moisture. Keep tree branches and other plants cut back from the house. Sometimes pests use these branches to get into your home.* Make sure that there are no cracks or little openings around your house. Sometimes pests use these to get into your home. Make sure that firewood and building materials are not stored next to your home. Pests like to build nests in stacks of wood.

Baiting using several types of baits may be effective or at least will aid in tracking a nest site. Residual flushes, aerosols, and dusts may be used successfully.

White-Footed Ant

White-Footed AntSize:

About 1/8-inch long

Color:

Black, with pale tarsal segments at the end of all six legs, giving it its name.

Behavior:

White-footed ants may develop huge colonies containing thousands of workers and numerous queens. A colony of white-footed ants can number up to one million individuals. This species may be difficult to control and does not feed much on ant baits. The keys to control are to find the colonies and sub-colonies and treat them directly. Regular inspections and service are necessary to find and treat new colonies as they move from neighboring properties. The services of a professional, such as Terminix, are very helpful when encountering these ants.

White-Footed AntThe white-footed ant is a serious pest in southern Florida and on the Hawaiian Island of Oahu. These ants nest outdoors under items on the ground, within landscape mulch, beneath loose bark on trees, under ground cover, in potted plants, and within piles of items, such as lumber, firewood, or bricks. Nests may also be readily established inside homes in walls, beneath carpeting, and in other suitable voids or spaces.

Prevention

Eliminate standing water. Pests, such as ants, are attracted to moisture. Keep tree branches and other plants cut back from the house. Sometimes pests use these branches to get into your home.* Make sure that there are no cracks or little openings around your house. Sometimes pests use these to get into your home. Make sure that firewood and building materials are not stored next to your home. Pests like to build nests in stacks of wood.

Baiting using several types of baits may be effective or at least will aid in tracking a nest site. Residual flushes, aerosols, and dusts may be used successfully.

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