The World of ANTS • Vol. 17: #53

While you certainly don't welcome their arrival at your picnic or kitchen pantry, the presence of ants is a fact of life we just have to accept -- and they're here to stay. While you probably regard them simply as a nuisance, there's a lot more sophistication to their existnece than you know. This week, Tidbits looks at the lowly ant and presents some facts that might give you more appreciation and respect for these ubiquitous and clever little critters.

• Ants are the most dominant insect on Earth. With an average of 250,000 brain cells, they are also considered to be one of the smartest insects on the planet, along with bees. (A human has about 100 billion brain cells). The word “ant” springs from the German word meaning “the biter.” • Ants belong to the order Hymenoptera, from the Greek words “hymen” meaning membrane and “ptera” meaning wings. This order includes wasps and bees. • There are over 15,000 different species of ants, and they are found on every continent except Antarctica. The densest populations are found in tropical regions. A single acre of Amazon rainforest may be home to upwards of three million ants. Almost half of the world’s ant population lives in tropical rainforests, yet they also can be found in arid sub-Saharan Africa, in the arctic tundra, and in caves.

• Most worker ants live only for a few weeks or months, while the queens can live for decades. The oldest recorded queen ant lived for an astounding 30 years.

• Because ants are not adept at crossing bodies of water, many remote islands were completely ant-free until humans began widespread trade carrying their goods by ship. The dumping of ballast was particularly effective at transporting ants, as was the exchange of certain trade goods, particularly lumber and agricultural products. Today there are over 50 species of ants in Hawaii, and none are native.

ANATOMY

• Although having no ears, ants detect sound by sensing vibrations in the ground through their legs. Likewise with no nose, they are able to detect smells with their antennae.

• Ants also don’t have lungs. Oxygen enters through tiny holes all over the body called spiracles, and carbon dioxide leaves through the same holes. The spiracles are connected to a network of tubes which distribute the oxygen throughout their bodies

Ant anatomy.

• Ants have two stomachs. One of their stomachs is for holding food for their own consumption, while the second one is to hold community food to be shared with other ants. This process is known as trophallaxis, from the Greek words meaning “nourishment exchange.” It allows ants who forage for food to feed those that stay behind and tend to the duties of the queen and the nest. The practice is so ingrained that if yellow ants are fed a red-dyed honey, the entire colony soon turns red.

BEHAVIOR

• Ants communicate in complete thoughts using the scent of their pheromones: “Emergency! Enemy ants! Follow me! I've found food!”

• Ants often attack the nests of other ant species not only to steal food but also to swipe the eggs of the defeated colony, which they take back to their own nest and tend. When the eggs hatch, the new ants become the “slave” ants for the colony. • Do ants sleep? Sort of. The average worker ant takes approximately 250 “power naps” each day, with each nap lasting just a minute or two, adding up to about four or five hours of sleep every day. By contrast, the queen ant takes about 90 naps per day with each nap lasting about six minutes, for a total of about nine hours of sleep per day. At any given time, 80 percent of worker ants will be awake while the other 20 percent are napping. When ants are asleep their antennae move involuntarily, similar to the way our eyes move when we enter REM sleep, indicating the state of dreaming. Ants have even been observed preparing a “bed” to take a nap on, by scooping out a smooth hollow place before dropping off to sleep.

• A swarm of army ants can consist of up to 700,000 ants that can move at speeds up to 66 feet per hour. To cross crevices, streams, or other obstacles, they link legs and jaws together to form living bridges.

• When the size of an anthill reaches an overpopulated state, the time is right to start new ant colonies. On a warm and humid day, masses of flying ants leave the nest. Some are male and some are female. This is the only time male ants make an appearance. • Mating takes place on the wing high in the air, hence the need for calm weather. Afterwards, females drop to the ground and shed their wings, while males quickly die. Fertilized females choose a nest site and burrow into the soil, made softer from recent rain. Once underground, the queen will not eat for weeks, until she has laid eggs and produced a set of daughter workers. The new ant queen uses energy from her fat stores, and from reabsorbing the muscles of her shed wings. The queen never mates again. • When the queen of the colony dies, the colony can only survive another few months. Queens are rarely replaced and the workers are not able to reproduce.

WORK DUTIES

• As they age, ants are assigned progressively more difficult roles within the nest. They may start out as nannies, tending to larvae. From there they may move up to the job of maintaining the anthill. Next they are promoted to sentinel or perhaps forager. Finally they are assigned to the mos

t dangerous job of warrior. Because of their age, they are expendable. All the ants you see fighting other ants are little old lady ants, pitted against other little old lady ants. • Ants keep regular daily shifts for working, sleeping, and eating. • Many species of ants are “farmers” tending

to aphids, scale insects, or mealybugs. These insects suck the sap of plants, and their excretions are sweet and edible. The ants protect these bugs from predators and shelter them from storms in order to keep eating this “honeydew.” Sometimes the ants will also eat the same bugs that produce it for extra protein. • Other ants farm specific types of fungus, carrying leaves into underground chambers and chewing them up to provide material for the fungus to grow on. They then harvest and eat the fungus. • Though an ant may follow a meandering path when foraging for a food source, it makes a straight line back to the nest once the food has been discovered and communicates the news to the rest of the colony. • Ant colonies of every breed have a distinctive chemical profile that enables members of the group to recognize one another and alerts the colony to the presence of strangers. Any ant with a scent that does not match the signature smell of the colony will be attacked and killed immediately.

• The largest known single ant colony stretches amazingly some 3,700 miles from Italy, through France, and into Spain. Any ant from this contiguous colony can be transplanted to any other place and still be accepted as a member of the group.

• North America's red imported fire ants have a painful bite which causes an intense burning sensation -- hence the name.

Red imported fire ants have a painful bite.

Fire ants cost the U.S. millions in veterinary and medical bills every year. They have also been known to cause extensive damage to farmers' crops. □