Ants are successful because they are social insects often forming complex colonies. The presence of ants in nature ensures the health of the environment. However, ants are not so welcome in our homes and buildings.
About 700 species of ants occur in the United States and Canada. Of these, only about 25 species commonly infest homes. Pest ants are usually divided into two groups based on their typical nesting preferences, either wall-nesting or ground-nesting. The 5 most common wall-nesting ants are the carpenter, crazy, odorous house, pharaoh and thief ant. The most common ground-nesting ants are the argentine, pavement (predominate species found in the Sun Cities area), little black, velvet tree, and the fire ant. Identification is the first step to controlling ants.
The segment between the thorax and abdomen is called a pedicel and has either one or two segments called “nodes.”
What ants are feeding on is a good place to start in identification and when selecting baits. See ant food preferences.
Nest location is often crucial, determining if the ants are coming from outside or under the structure. In Arizona baiting is often the most effective way to control house invading ants. Perimeter barrier treatments are usually effective in preventing outside entry.
Registered pesticides for ant control vary from state to state.
Have a question about controlling ants? Post it on IPCO Message Board
This light to dark brown ant, about one-tenth inch long; antenna has 12 segments. The Argentine ant is readily adaptable and can nest in a great variety of situations. Colonies are massive, and may contain hundreds of queens, nests are usually located in moist soil, next to or under buildings, along sidewalks, or beneath boards.They travel in trails, forage day and night. This ant can eat almost anything but prefers sweets. It has no important natural enemy in the United States.
These ants are large. They are a nuisance by their presence when found in parts of the home such as the kitchen, bathroom, living room, and other quarters. They do not eat wood, but remove quantities of it to expand their nest size, sometimes causing structural damage. Winged males are smaller than winged queens. Wingless queens measure 5/8 inch, winged queens 3/4 inch, large major workers 1/2 inch, and small minor workers 1/4 inch. Workers have some brown on them, while queens are black. Workers have large heads and a small thorax, while adult swarmers have a smaller head and large thorax. The petiole has one node and the profile of the thorax has an evenly rounded upper surface (workers only).
These ants will feed on sweets and kitchen scraps, but prefer to feed on animal matter and insects such as fly larvae and adults. Ants present the appearance of running aimlessly about a room, and thus, named “crazy.” Workers are about 1/10 inch long, with slender long legs, dark brown to black in color, one node petiole, the profile of the thorax not evenly rounded and the abdomen tip has a circular fringe of hairs.
The notorious Red Imported Fire Ant , the American South’s “ant from hell,” was accidentally introduced into the port of Mobile, Alabama, sometime in the 1930’s. Its native range is northern Argentina and southern Brazil, and the first immigrant colonies probably made their ways north as stowaways on cargo ships. The species then spread throughout the southern United States, where today its vast populations of fiercely stinging workers make it a major pest.
Link: Imported Fire Ant – FAQ
If you want to locate harvester ants, look for a ring of seed husks around the nest. Harvester ants collect and store seeds. In the nest, using their powerful jaws, the largest workers remove the husks, then throw them outside the nest. They chew the kernels into a soft pulp and feed it to the growing larvae. During drought, if the adult ants are unable to find anything edible outside the nest, they will eat the seeds too.
During rainy periods, the ants will not allow the seeds to become damp, otherwise they would sprout or get moldy. When there is a dry day, the workers take the seeds outside to dry in the sun, then carry the seeds back again into storage. Sometimes these clever little ants will bite out the embryonic root of the seed to prevent sprouting.
Harvester ants can be found almost everywhere in the world. In the Southwestern United States, their huge mounds are a common sight. The nest of colonies of harvesting ants is like a village. The mound above ground may be 20 to 30 feet (6 to 9 meters) across and 6 feet (1.8 meters) or more into the ground, with 60,000 to 90,000 members.
Little Black Ant
These are the common house ants which nest in woodwork, masonry, soil, and rotted wood. They feed on sweets, meats, vegetables, honeydew and other insects. Workers are about 1/8 inch long, slender, shiny black, sometimes dark brown with two nodes in the petiole and a 12-segmented antennae with a three segmented club. Nests in the ground are detected by the very small craters of fine soil.
Odorous House Ant
These ants occasionally forage indoors for sweets and other foods. They give off an unpleasant odor when crushed, smelling like “rotten coconuts.” Workers are brown to dark-brown in color, about 1/10 inch long. The petiole has one node (hidden by the abdomen) and the profile of the thorax is uneven.
Link: Odorous House Ant
This is one of the most common tiny house-invading ants with nests usually found outdoors under stones, in pavement cracks, along the curb edges, in crevices of masonry and woodwork. Pavement ants may forage in the home throughout the year, feeding on grease, meat, live and dead insects, honeydew, roots of plants and planted seeds. Workers are sluggish, between 1/12 to 1/4 inch long, light to dark brown or blackish. In winter, nests may be found in the home near a heat source.
This ant is a serious nuisance in hospitals, rest homes, apartment dwellings, hotels, grocery stores, food establishments, etc. They feed on jellies, honey, shortening, peanut butter, corn syrup, fruit juices, soft drinks, greases, dead insects and even shoe polish. They have been found in surgical wounds, I.V. glucose solutions and sealed packs of sterile dressing in hospitals. These ants are capable of mechanically transmitting diseases, Staphylecoccus and Psuedomonas infections in hospitals. Workers are very small about 1/16 inch long, light yellow to reddish-brown colored with the hind portion of the abdomen somewhat darker. The petiole has two nodes and the thorax is spineless. The antennae has 12 segments with the antennal club composed of three segments.