ANTS: PHERMONES, QUEENS, COMMUNICATION, HUNTING AND ENSLAVEMENT

ANTS

Ants have been around for at least 140 million years, and they are believed to have evolved from wasps. There are 12,000 known ant species (1.4 percent of all known insect species) and an estimated ten thousand trillion individuals ants. Their total weight is about equal to all the people in the world and is ten times that of all other insects combined. They are found in every part of the world except the polar ice caps and permanently ice-bound mountains. [Source: Bert Hölldobler, National Geographic June 1984 [┶]

If any group of species were to be labeled as king of the jungle it would have to be ants. They, not lions (who don't live in the jungle anyway), rule in terms of numbers, ferocity and organization. Describing an encounter with a hostile group of ants Harvard biologist and ant expert Edmund O. Wilson lamented: "The little defenders were under my clothing, in my hair, running over my eyeglasses. I had to stop frequently to clean myself off, and finally I gave up. But that, of course, is the point. I was Gulliver tied down by the Lilliputians in a successful defense of their land. Although I was 80 million heavier than each ant, the tribe prevailed."▸

Many ants and termites spend their whole life underground. Those that dig often lack eyes and have narrow bodies. They generally excavate the earth with their mouths.

Ants are omnivorous. Typically a species will eat a mix of aphid feces, cricket wings, other ants, spingtails and seeds. They are the largest consumer of other insects and the primary scavenger of small dead bodies.

Websites and Resources on Ants: Antweb antweb.org ; Antbase Database antbase.org ; BugGuide bugguide.net/node/view/165 ; Websites and Resources on Insects and Bugs: BugGuide bugguide.net ; Amateur Entomologists' Society amentsoc.org ; MDPI Insects mdpi.com/journal/insects; National Geographic on Bugs National Geographic ; Smithsonian bug info si.edu/Encyclopedia_SI/nmnh/buginfo ; Insect Images.org insectimages.org ; Obervations, the Naturalist inaturalist.org/observations ; Safrinet Manual for Entomology and Arachnology SPC web.archive.org

Book: “Adventures Among Ants: A Global Safari with a cast of Trillions” by Mark Moffett

Websites and Resources on Animals: Animal Diversity Web animaldiversity.org ; BBC Earth bbcearth.com; A-Z-Animals.com a-z-animals.com; Live Science Animals livescience.com; Animal Info animalinfo.org ; Encyclopedia of Life eol.org , a project to create an online reference source for every species; World Wildlife Fund (WWF) worldwildlife.org the world’s largest independent conservation body; National Geographic National Geographic ; ; Endangered Animals (IUCN Red List of Threatened Species) iucnredlist.org ; Biodiversity Heritage Library biodiversitylibrary.org

Ant Colonies

Like termites, ants live in colonies in which the vast majority of the members work their butts off gathering food, tending young, fending off intruders and building living space to support a structure that allows one or a few individuals to reproduce. Ants are unable to live alone. They do everything for the common good of the colony.

Ant colonies, which may have a million or more individuals, are made up entirely females produced by a single queen. Their sole purpose in life is to protect the queen and make sure that enough food is gathered to feed the next generation. The Japanese word for ant — written by joining the Chinese characters for “insect” and “loyalty”’seems like an apt way to sum up their existence.

See Termites

Male and Female Ants

ant morphology

All ant societies consist entirely of females. Males come into existence for only a short time to fertilize the queen and then die. Almost all ants in a colony are daughters of the same queen. They are made infertile by chemicals and their size and caste is determined by the food they are given. Each ant on average shares 75 percent of her sister' genes. These ants have no chance of reproducing so it makes sense from an evolutionary point of view for them to die for good of colony.

Males are created on rare occasions when a female destined to be a queen becomes fertile. They are hatched from eggs unfertilized by the queen and their production is signaled by natural occurrences. They don't live for very long and their sole purpose in life is to mate with the queen.

The males and the virgin female slated to be queen have wings. If a male is lucky enough to locate the fertile female he grabs onto her with his mandibles. Some males blow their opportunity, grabbing the female too hard and cutting her abdomen in two. The queen tries to mate with as many males as possible to fill her abdomen with enough sperm to last a lifetime and fertilize millions of eggs. The transfer of sperm takes place in mid flight.

Queens, Soldiers and Worker Ants

After the queen's abdomen is full of sperm she produces a vibrational signal letting the males know it is time for them to let go. She then flies off and, after she located a nesting site, she sheds hew wings and buries herself into the ground to raise her young. Once she has established here colony she never sees the light of day unless scientist or an ant-eating animals digs her up. The first generation of offspring are fed from her own body reserves.

The vast majority of the colony is made up of worker ants who perform a variety of duties and will sacrifice themselves at a moment's notice for the colony. They often live only a few months and are divided by size into minors, media, submajors and majors, which each size responsible for a specific duty such a carrying prey or feeding the queen’s larva. Soldier ants, or majors, are in charge of defending the colony. They may be a hundred times bigger than the smallest worker ants. Some are so ferocious they will even attack encroaching plants.

Once a colony is established the queen is taken care of at all times by workers who feed her sterile eggs and regurgitate food. Responding to chemicals given off by the queen the workers of some species of ant vigorously lick and groom their mother's body. The queen lives for several years. If she dies before a new queen is born the colony is thrown into chaos and often collapses.

Ant Communication

Ants are for all intents and purposes blind and deaf. To get around, communicate and gain information about their world they rely on touch from the sensitive antennae and the smell of chemicals called pheromones, that are secreted and sensed by smell and taste are used like language to communicate warnings and instructions.

Wilson wrote in National Geographic: “The communications systems of ants are radically nonhuman. Where we use sound and sight, they depend primarily on pheromones...Since the brain of an ant weighs less one-millionth as much as a human brain, it is not surprising that a given species produces just ten to twenty signals. Unlike human language, these messages are entirely instinctual.”

Pheromones convey messages about the presence of danger and food, identify ants as friends or foe, and provide information about the rearing of young. Weaver ants release a series of pheromone that call for reinforcements when they bite an intruder and relay information about the location of food by leaving pheromones trails. Some species have huge workers that are signaled by pheromones to attack large intruders such as human, armadillos or anteaters.

Navigating Ants

University of Zurich biologist Rüdiger Wehner discovered that some ants navigate by following directional cues such as the way light from the sun is polarized at certain times of the day. In a study of Tunisian ants that scamper across 160̊F desert sands to collect victims that die in the heat he discovered that an ant's eye has "80 lenses dedicated to receiving polarized light in the ultra-violent range of the spectrum, each from a different point in the sky.”

"One lens from 180 degrees, another from 270 degrees and so on," says Werner." To his test his theory he built a device that look like a lawn mower to mask the polarity. In accordance with his theory ants have difficulty finding their way around but observers thought he was trying to mow the desert. [Michael E. Long, National Geographic, June 1991]

German researchers found ants some in the Sahara that using a zag zag pattern when looking for food but take a direct route home found that do so in part by counting their steps. The scientist discovered this by clipping the legs of some ants and lengthening the legs of others . Those had their legs clipped began look for their nest before they arrived and those that had their legs lengthened overshot their target.

Ant Group Behavior

As individuals ants are often clueless about what they are trying to do. “If you watch an ant trying to accomplish something you’ll be impressed by how inept it is,” Deborah Gordon, a biologist at Stanford University, told National Geographic.

“A colony can solve problems unthinkable for individual ants,” Peter Miller wrote in National Geographic, “Such as finding the shortest path to the best food source, allocating workers to different tasks, or defending a territory from neighbors. As individuals, ants might be tiny dummies, but as colonies they respond quickly and effectively to their environment.”

“One key to an ant colony,” Peter Miller wrote in National Geographic, “is that no one’s in charge. No generals command ant warriors. No managers boss ant workers. The queen plays no role except to lay eggs. Even with a half million ants, a colony functions just fine with no management at all — at least none that we would recognize. It relies instead upon countless interactions between individual ants, each of which is following simple rules of thumb. Scientist describe such a system as self-organizing.”

Research by Gordon with harvester ants reveals that each day the colony calculates how many ants to send out to forage for food, with the number changing based on changing conditions. The first members of the colony that go out are patrolling ants. Foragers and workers wait for the patrollers to return before going out and the rate of the patrollers return determines whether they go out. “When a forager has contact with a patroller it is a stimulus for the forager to go out,” Gordan said. “But the foragers needs several contacts less than ten second apart before it will go out.” Gordon made this discovery by dropping beads’some scented with patroller scent and some scented with worker scent — at the entrance of their nest and found that foragers only responded to the beads with patroller scent. She also found that once the foraging process gets going the rate foragers go out depends on the return rate of the foragers that went before them.

The behavior described above can be explained by swarm intelligence, which is base on the idea that creatures abide by simple rules, each individual acting on local information . No individual sees the picture, no one tells individuals what to do, no leadership is needed. Oxford biologist Iain Couzin told National Geographic, “Even complex behavior may be coordinated by relatively simple interactions.” In 1991, Marco Dorigo, a computer scientists at the University of Brussels, created a mathematical model to solve complex human problems based on ant behavior. The model has been particularly useful to trucking firms trying to figure out the best way to distribute their goods and airlines determining the best way to get their planes in and out of gates and customers in and out of check in counters.

Studies of army ants by Iain Couzin of Oxford University found that the behavior of workers was different depending on whether they were heading away from the nest or heading towards it, with those heading back more or less moving in a straight line and those go out making slight turns when they encountered ants coming the other way. Using these methods ants were able to move rapidly along a sort of highway that had only just been created with a pheronome trail.

Ant Hunting and Enslavement

Many ants are carnivorous. They are especially fond of termites. Many species specialize by raiding termite colonies. Ants themselves are preyed upon by a host of creatures including white-plumed antbirds and body-invading fungus.

Mark Moffett, an ant expert and research associate at the Smithsonian Institute, told the Los Angeles Times, “Most ants either hunt on their own or send out scouts to search individually. You can spread out and look around alone, because in spreading apart, you’re to have a greater chance of finding something. But after one of the scouts doesn’t find something’say a prey she wants to kill’she often has to go get help, which give the prey lots of time to escape...Mass hunting is searching in a group. Army ants put soldiers together in a tight group that moves forward together. When they find something, they use the shock-and-awe effect. You find less but kill more.”

Some kind of ants make slaves of other species of ant, raiding colonies of the slave ants and seizing their pupae and make slaves them. Moffet said, “All you have to do is trick a young ant into thinking it is part of your colony and it will work to death for you.”

Ants and Other Living Things

Some ants tend aphids and mealybugs and feed on their sweet, slimy excrement sometimes called honey-dew. The aphids are tended like cattle and goaded into producing more honeydew than they otherwise would by stroking their antennae and squirting them with formic acid. When the aphids die their eggs are carefully incubated so a new generation can be raised.

Many ants have a birds-and bee-like relationship with plants in which the plant provides the ants with food, often in the form of nectar, while the ants help to spread pollen and fertilize the plants. Some ants also defend plants against pests in return for food, often nectar. [Source: Mark Moffett, National Geographic, February 1999 and May 1999]

Thousands of plants rely on ants to disperse their seeds. Many ant species collect seed of certain plants and take them to their colonies, helping the plants germinate by providing them with nutrients to grow. In many cases the ants are tricked into gardening the seeds. Many seeds contain a small fatty appendage known as an elaisome which attracts ants. The elaisome is fed to larvae and the rest of the seed is thrown with other ant garbage that not coincidently provides the seed with nutrients that help it grow.

Often when a seed falls off a tree ants will show up to carry it back to their nest, often by grasping the elaisome with their mandibles. Some colonies handles tens of thousands of seeds. Plants are thought to have evolved the elaisomes as means to getting a seed to a more advantageous spot. Seeds on the forest floor often have few other options than relying on ants. Birds and flying insects are fine for distributing seeds on the trees but are not so good at dispersing ones on ground level. Some questions about the method remain, such as why ants don’t just remove the elaisome instead of carry the whole seed back to their nest and what help the ants offer the plants in that they generally don’t move the seeds very far from where they fall.

Three-Month-Old Phoenix Girl Killed by Ants During Nap

In May 2023, a three-month-old girl was killed by ants while taking a nap in a crib at a baby-sitter's home in the afternoon in Phoenix, Arizona, police there said. According to the Arizona Republic: The caregiver, who has not been identified, put the infant down for a nap about 1:30 p.m., police Detective Tony Morales said. When she went to check on the little girl a half-hour later, she was covered in ants and was in "severe respiratory distress," he said. [Source: Susan Carroll and Judi Villa, Arizona Republic, May. 20, 2003]

Autumn White had "hundreds of ant bites" on her legs and her throat was swollen, Assistant Phoenix Fire Chief Bob Khan said. She was not breathing when firefighters arrived at the home near 83rd Avenue and Mohave Street. "A child that age probably just couldn't take the venom," Morales said. Khan said the baby may have had an allergic reaction, with the poison from the ants causing her respiratory problems. At least 40 deaths occur annually in the United States from reactions to insect stings. A severe allergic reaction, anaphylaxis, occurs in 0.5 to 5 percent of the country's population, ccording to the American Academy of Allergy, Asthma and Immunology. Children and senior citizens are more vulnerable. Lower resistance "Their resistance is less," Khan said. "They don't have the ability to recover like adults do."

Autumn was flown to St. Joseph's Hospital and Medical Center. After the little girl died, firefighters again were dispatched to the home, where the baby-sitter was so distraught that she was taken to an emergency room for treatment. The black ants in the baby-sitter's home were about one-eighth of an inch long and apparently crawled into the home between the carpeting and the wall, police said. Neighbors in the new, upscale tract home development in southwest Phoenix said they started noticing more ants when daily temperatures started rising. Mark Cedre, 29, said for months that the worst problem was the ants searching out "sugar in the pantry." But when he pulled up the carpet in his home this weekend to put in hardwood floors, Cedre found ants crawling along the foundation. "I fumigated the whole thing," he said. "I was stomping all weekend, like a mariachi. "My wife is nine months' pregnant; she's due any moment," Cedre added. "She's freaking out. She wants the whole neighborhood fumigated now."
Black ants live in colonies much like bees and forage widely in search of food. Most ants have well-developed jaws and can bite. Khan said that while it's highly unusual for a person to die from ant bites, it's very possible for a person to have an allergic reaction which, if serious enough, could be fatal. Shock symptoms Symptoms of an anaphylactic reaction include swelling of the lips, throat, ears, eyelids, palms and soles; hives; dizziness; wheezing or shortness of breath; and a sudden drop in blood pressure.

Experts say that without medical treatment anaphylactic shock can lead to death in less than an hour. "It's like a bee sting," Khan said. "Your respiratory system freezes up and you're not able to breathe. It's like a real bad asthma attack." Neighbor Lorena Nieto, 26, held her 14-month-old son on her hip just down the street from where Autumn died and whispered to her baby: "It's scary, huh?"

Image Sources: Wikimedia Commons

Text Sources: Mostly National Geographic articles. Also David Attenborough books, Live Science, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, and various books and other publications.

Last updated December 2024