Ants

Ants are among the most prevalent pests in households. They are also found in restaurants, hospitals, offices, warehouses, and other buildings where they can find food and water. On outdoor (and sometimes indoor) plants, ants protect and care for honeydew-producing insects such as aphids, soft scales, whiteflies, and mealybugs, increasing damage from these pests. Ants also perform many useful functions in the environment, such as feeding on other pests (e.g., fleas, caterpillars, termites), dead insects, and decomposing tissue from dead animals.

Inside buildings, household ants feed on sugars, syrups, honey, fruit juice, fats, and meat. Long trails of thousands of ants may lead from nests to food sources, causing considerable concern among building occupants. Outdoors they are attracted to honeydew, produced by soft scales, mealybugs, and aphids. This liquid excrement contains sugars, and other nutrients. Frequently outbreaks of scales and aphids occur when ants tend them for honeydew because the ants protect scales and aphids from their natural enemies.

Ants have been living on the Earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20,000 different species of ants. For this reason ants have been called Earth's most successful species.

Ants can bite with their pincerlike jaws, although most species rarely do. The velvety tree ant, however, is an aggressive biter. A few ants sting, including native fire ants and harvester ants, which are primarily outdoor species.

Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnel up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in large groups searching for food.

Ants are social insects, which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers, and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends the rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa, and adult.

Ants have three main parts. The head, the trunk(middle section), and the rear or metasoma. All six legs are attached to the trunk. The head consists of the jaws, eyes, and antennae. The eyes of ants are made up of many lenses enabling them to see movement very well. The antennae are special organs of smell, touch, taste, and hearing. The metasoma contains the stomach and rectum. Many species of ants have poison sacks and/or stingers in the end of the metasoma for defense against their many predators. To see a diagram and learn more about ant anatomy visit our Ant Anatomy page.

Ants do not have lungs. Oxygen enters through tiny holes all over the body and Carbon Dioxide leaves through the same holes. There are no blood vessels. The heart is a long tube that pumps colorless blood from the head back to the rear and then back up to the head again. The blood kind of coats the insides of the ants and is then sucked into the tube and pumped up to the head again. The nervous system of ants consists of a long nerve cord that also runs from head to rear with branches leading to the parts of the body, kind of like a human spinal cord.

If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow.

There are over 12,000 species of ants throughout the world. In the United States there are about 200 species but fewer than a dozen are important to us as pests. One of the most common ant occurring in and around the house and garden in is the Argentine ant, Linepithema humile. Other common ant pests include the pharaoh ant (Monomorium pharaonis), the odorous house ant (Tapinoma sessile), the thief ant (Solenopsis molesta), and the southern fire ant (Solenopsis xyloni). The velvety tree ant, Liometopum occidentale, nests in old wood and is a common outdoor species in landscapes.

Of great importance, is the red imported fire ant, Solenopsis invicta, which has recently gained in greater numbers throughout the southern United States. In some areas, the spread of the fire ant has been slowed by competition from the Argentine ant.

Carpenter ants, Camponotus spp., also invade buildings all over America. Although they do not eat wood as termites do, they hollow it out to nest and may cause considerable damage.