Ants are familiar to everyone as they seem to be everywhere. No one knows the true number but estimates suggest that from 100 trillion to 10,000 trillion ants are living on the planet today.
Over 700 species of ant can be found in the US with new ones arriving regularly. The majority are harmless and even beneficial. Some feed on a range of other pests, including termites.
Despite these benefits, the National Pest Management Association reports that ants are viewed as the number one nuisance pest in the country. This is due more to their constant presence, attracted by anything sweet, than the aggressive and destructive nature of some species. Fortunately, only about 25 species cause enough trouble to be classed as true pests.
Ants are complex insects, with distinctive habits and behaviors. They employ a variety of defense techniques and are often at war with other kinds of ant. New invaders occasionally push out established species. Even they can be threatened by more recent arrivals, such as the newly introduced Fire ants now losing ground to an influx of Crazy ants.
Ants, especially winged ants, may be confused with termites but can be distinguished by their thin ‘waists’. Termites are a uniform width the full length of their bodies, whereas all ants have a distinct narrowing between the thorax and the abdomen.
In the US, ants can range in size from less than 1/16 inch to 3/4 inch long. They live in colonies that may contain hundreds of thousands of individuals.
Colonies comprise a queen, some males, and many sterile female workers. Workers forage for food and water, bringing it back to the nest. The queens and males of most species cannot feed on solid food. Pre-digested food is passed from the workers to these by a method called trophallaxis.
Generally, ants eat a variety of foodstuffs. A few, like leaf-cutter ants, have specialized tastes. Most are drawn to sweet things, such as sugars, and leave pheromone trails so others can find the source easily. Their food preferences may vary during the year as the colony grows and its dietary needs change.
Although many types can be recognized easily, the majority are difficult to identify correctly without experience.
Like other insects, an ant goes through various stages during its life: egg, larva, pupa and adult. The time it takes to develop depends on the species, food availability, and temperature. For many, the cycle takes six to eight weeks.
Ants are social insects, with a fixed caste system. The queen is central to the colony. She lays the eggs and produces the pheromones that determine which larvae become workers, males or future queens.
Queens can be long-lived, some reaching fifteen years. Even workers may live for several years. Periodically, the queen will lay eggs that develop into other fertile females and additional males, both of which have wings. Winged ants are called alates. They leave the nest to form new colonies. A mass emergence is often triggered by spring rains or thunderstorms.
Colonies can spread either by alates founding new nests after swarming or by budding. This is when one or more queens leave a nest with workers who help to establish a new colony. Many of the kinds that spread by colony budding, such as Fire ants and Argentine ants can be difficult to eliminate.