General Description

While ants contribute positively by conditioning the soil and preying upon termites, caterpillars and other pests, ants themselves often become pests. Their nests and mounds are considered unsightly where they are not wanted, and ant nests in structures can damage property. Ants consume and contaminate food, and some species sting people, pets and livestock.

Like all insects, ants have three body parts: head, thorax and abdomen. At the ant’s waist (between the thorax and abdomen) is one or two expanded segments known as nodes. The number and shape of these nodes are useful features for identifying ant species. Ants also have “elbowed” antennae; a joint at the middle of each antenna allows it to bend like an elbow. The winged form of ants have two pairs of wings, with the forewings longer than the hind wings.

Ants are social insects that live in colonies. They cooperate with their nest mates to maintain a caste system of individuals that perform specific tasks.

An ant develops through egg, larval, pupal and adult stages. The white “ant eggs” carried by workers when an ant colony is disturbed or moving are not the eggs but the pupal stage of complete metamorphosis. Ant eggs are almost microscopic. The larvae that hatch from them are helpless, grub-like young that the workers must feed and care for. A larva grows, enters the pupal stage and later emerges from its cocoon as either a worker or reproducer.

General Control

Often the first reaction to seeing a line of ants trailing inside the home is to grab a can of pesticide and spray them. This strategy usually results in a few dead ants. Unfortunately, it treats only the symptoms of an ant problem. Routine spraying of ants and their trails rarely provides the cure, since there are a lot more ants where those came from.

For most integrated pest management programs, including those for ants, exclusion is the first line of defense. This involves taking steps to prevent pests from entering the structure. Most often, ants nest outside a structure and make periodic “raids” indoors in search of food. Sometimes they enter the structure and establish nests inside it. Inspect for ant entry points around the foundation outside, and inside crawlspaces and basements. Apply a sealant, such as silicone caulk, to gaps where ants are entering the structure, and to potential entry points.

Another management tool is sanitation. For ant management this means keeping vegetation, mulch, landscape timbers, firewood and debris away from the structure’s foundation, as these items harbor ants and some insects ants feed on. Moisture also attracts insects, so leaky faucets and pipes, faulty grades, clogged gutters and downspouts should be repaired. Ants usually enter structures in search of food, so sanitation indoors means keeping foods tightly sealed. Making food unavailable to ants not only discourages them from establishing trails into a structure, but makes them more likely to accept baits. Conventional pesticides, such as liquids, dusts and granules, can be part of an ant management plan. Always read the label and follow label directions.