Articles

Antsy Ant Antics

By Matthew Vanhorn and Bert Thompson, Ph.D.

There are more of these creatures than any other on the planet, and their combined weight is greater than the combined weight of all humans. What are they? Ants! Weighed on a scale, ants would account for 10 percent of the mass of the world’s land animals. An ant can lift a weight 50 times as heavy as its own body (if a 175-pound man could do that, he would be able to lift more than 4 tons!). They build bridges, raise crops, and work as carpenters. There are ant nurses, guards, soldiers, hunters, trappers, and even undertakers. Some of them live in underground tunnels; some build mounds out of dirt; and others live in dead trees.

Ants are known as “social insects.” Social insects live in groups, and share the work of the colony so they can survive. These insects usually build nests in which they raise their young and store food. Inside each nest, one insect—the queen—lays eggs, and all the other insects are her offspring. Workers look after the eggs, find food, raise the young, and defend the colony against invaders. Every year, some of the males and queens fly away and mate. After mating, the male dies and the queen starts building a new nest. There are more than 10,000 different types of ants. And though all of these 10,000 are very interesting, we would like to discuss here only five types.

HONEYPOT ANTS

Animals that live in desert regions where there sometimes is little food or water often do things differently from animals that live where food and water are plentiful. A good example of this is the “honeypot ant,” which lives in deserts in the western United States, Mexico, and Australia.

As most ants do, this particular species exists in colonies, which can vary in size from a few hundred to several million individuals. Each colony consists of a queen, workers, and males. The queen can lay as many as 1,500 eggs per day.

Most of the time, these ants live off a liquid called “honeydew.” Insects like aphids (plant lice) suck juices from plants for food, but these juices often contain more sugar than the aphids can use, so they discharge the excess as honeydew. When ants locate the honeydew (like on the leaves of plants), they lick it up and use it as their own food. On occasion, ants will even “milk” aphids to get them to release the honeydew. The ants “stroke” the aphids with their antennae, causing the aphids to release more honeydew, which the ants then eat.

However, at times (especially in the desert) it is difficult to find plants and aphids. So, these ants store food for future use in a most unusual way. There is a group of ants within their society know as “repletes.” These ants have huge abdomens, which stretch easily. The repletes eat lots of honeydew when it is available, and then store it in their bodies for future use by the rest of the colony. In fact, these repletes have been called “living storage tanks,” which is how they got the name of “honey pot” ants. Their abdomens swell up so that they are many times their original size. In fact, the abdomen (called a “gaster”) gets so large that the honeypot ants can’t even walk. They simply hang motionless from the ceiling of the nest. One scientist several years ago discovered a colony of ants that had more than 1,500 “honey pots”!

When food becomes scarce, the ants in the colony go the honeypots and stroke them with their antennae, which causes them to regurgitate the honeydew so that the queen, workers, and males can eat it in order to stay alive and carry out their functions within the nest. Because the honeydew is composed mainly of sugars (known as glucose and fructose), it provides a lot of energy for the ants. But ants aren’t the only one who get energy from the honeypots. In Australia, there is a group of people known as the aborigines who have been known to dig up ant mounds, locate the honeypot ants, and eat them like candy because they are so sweet!

LEAFCUTTER (“PARASOL”) ANTS

Leaf-cutter ants include 100 varieties of small, spike-covered “farmers.” Leaf-cutter ants can be found in the tropical forests of Central and South America, and the southern states of the United States of America. Each colony is headed by a single queen, and can contain as many as eight million ants. These industrious ants collect leaves and petals by cutting them into small, semi-circular pieces using their sharp, pointed jaws. Because they carry pieces back home high above their heads, they are sometimes called “parasol ants.”

Incredibly, ants do not eat the leaves. Rather, they cultivate miniature gardens of fungus on pieces of leaves. which they chew and then store in underground compost piles. Several million ants usually inhabit their colonies, and the garden chambers can extend as deep as twelve feet underground. In order to fulfill all the needs of the colony, the ants divide the work among classes. Each class of workers is designed to do a special job. The biggest ants have powerful jaws to cut leaves, flower petals, and blades of grass. They bring these big pieces back to the nest where slightly smaller workers cut and dice the plant material into tiny lumps. The smallest workers chew these up into balls, adding bits of fungus. The ants’ saliva contains ingredients that help the fungus break down the plant material, and also kills harmful bacteria and other fungi.

Small workers strip off wax and other parts of the plants that the fungus cannot use. Workers dump this refuse into special waste chambers. The relationship between the ants and the fungus is symbiotic, meaning that both benefit. The fungus benefits because the ants feed it, protect it, and spread it from place to place. In return, the fungus grows a clump of special hyphae. Each clump is like an instant three-course meal, which the smallest ant workers use to feed the larvae.

ACACIA (“GARDENING”) ANTS

Some plants “hire” an army of ants to serve as their “bodyguards.” In exchange, the plants provide nectar for the ants. The ants protect the plant by attacking anything that might be hazardous to the plants—from small insects to large herbivores that attempt to eat the plant. The Acacia is the most famous example of “plant-ant” association. One group of Acacias that is found in Africa and tropical America gives ants all they need. Thick, hollow thorns sprout along the branches, providing ideal ant homes. Acacias also produce nectar at the base of their leaves, and little beads of oils and proteins called Beltian bodies.

Acacia ants are highly aggressive, killing insects that land on the Acacia, and inflicting painful bites on large herbivores. These ants will even chew up plants sprouting within a meter of the Acacia, and will chew any vines growing on the Acacia. This is vital, as Acacias require direct sunlight. Up to twenty-five percent of the ant colony is constantly on the plant, day and night, patrolling and cleaning the plant of fungal spores, spider webs, and dust.

Unlike other plants, the Acacia does not possess any chemical defenses, relying entirely on its ant bodyguards. As an experiment, scientists removed the ants from an Acacia plant. The plant suffered horribly from insect attacks, and died within a year. With the benefit of Acacia ants, the Acacias live for about twenty years. Conversely, the ants cannot survive without the Acacia’s gift of shelter and food.

CORNFIELD “DAIRYING” ANTS

Some ants flourish by engaging in peaceful agriculture. Dairying ants capture and domesticate aphids in order to milk them regularly for the sweet droplets of honeydew they excrete. Dairying ants will take care of these aphids, and ward off any of their enemies to ensure they remain well supplied in honeydew. In the case of the corn root aphid, dairying ants will collect aphid eggs in the autumn, and protect them in their nests over the winter. Then, in spring, the dairying ants will carry the young aphids to smartweed and grass roots, where they feed. These young nymphs grow to become wingless females, called “stem mothers” because they can produce live young without mating. These stem mothers raise two or three generations on the host plant, after which the ants return to carry the aphids to young corn roots where the aphids breed another ten to twenty generations.

The aphids flourish under the care of the ants. The ants gain the aphid honeydew excrement; the aphids gain nurses and protectors. The relationship is “mutually symbiotic.” The ants, however, control the relationship. When a winged female aphid is hatched and tries to fly off to a different host plant, the ants show their authority by seizing the female and carrying her back into their nest.

ARMY ANTS

Army ants of the Western Hemisphere and their African cousins, the so-called drivers, are fearsome tropical migrants with a reputation to match. These tiny marauders (sometimes numbering 2 million) march like a ferocious army, swarming over crops, homes, domestic animals, and wildlife, taking what they wish and leaving behind a pillaged land. The driver ants of Africa are the more vicious, having sharp mouths suited for cutting and tearing the flesh of vertebrate victims as well as vegetation and other insects. Terrorized animals take flight in anticipation of the ants’ arrival. Those too small or feeble to escape are killed and carried off to be eaten. People often find tethered goats, horses, or dogs that have had the flesh stripped from their bones.

There are very few, if any, creatures that are more noted for their fierceness than the deadly Megaponera ants. These ants go on ruthless search-and-destroy missions. The ants are led by a single scout, and specialize in termite extermination. They march into the termite nests, and swarm every hole and crevice of the victims’ stronghold and, one by one, drag the termites to the surface. When the attack iscompleted, the columns of warriors form once again, with each ant carrying three or four mutilated termites. As if proclaiming their triumph, the ants make shrill screeching sounds as they march back to their own nest.

These voracious attackers have a variety of weapons with which to assault the herbivorous termites. For example, the Malaysian Basicerotine ants are built for squeezing into narrow spaces, and their mouthpieces are perfectly formed clamps with which they grasp fleeing termites. The jaws of other species of ant soldiers are so adapted for fighting that the ants are unable to pass food to their own mouths, depending instead on the services of smaller laboring ants for nourishment.

ANTS BY CHANCE?

We can learn so many lessons from these creatures. We can look at them and realize how much good can be accomplished when everyone works together. Ants, through example, teach us that everyone has a vital role to fulfill in order to meet out the greater good of the colony. The Acacia ants teach us to attack what is bad, and to protect that which is good. And, from their tireless, industrious actions, we can learn to never, never quit. Ants are master designers, yet they were engineered by the Great Designer! The wise king, Solomon, once wrote: “Go to the ant…consider her ways and be wise” (Proverbs 6:6). How right he was!

REFERENCES

Sullivan, John R. (1990) “Marauding Masses,” Amazing Animals (Time-Life Books: Richmond, Virginia).

Thompson, Bert (2001) “Intriguing Insects!,” Discovery, 12:[3]:18, March.

http://www.apologeticspress.org/articles/print/2627