THE WORLD OF ANTS

adapted from articles by

Brian Grantham-Hill

B.Sc.

Used with the kind permission of the Creation Science Movement, 50 Brecon Avenue, Cosham, Portsmouth, England, P06 2AW.

Go to the ant, use sluggard!

Consider her ways and be wise,

Which having no captain,

Overseer or ruler,

Provides her supplies in the summer,

And gathers her food in the harvest.

Solomon, 10th century B.C.

Ant Communities

It has been said that no man is an island. Interdependence is also an attribute of the ant, which, like man, lives a communal life. An ant colony is founded by a fertilized queen who will lay eggs immediately after breaking off her wings. (The male usually dies soon after mating.) Sometimes queens come together in groups so as to improve the colony's chance of success.

The queen will become simply a large egg-laying machine, adjusting her output to seasonal needs. The first eggs laid develop into infertile female workers that will never grow wings. They collect food, tend the larvae in the nest, and feed the queen. Workers also labor to enlarge the nest, collecting materials and digging tunnels as required.

Alate (winged) males and females are reared only at certain times of the year. Eventually they will leave the nest for a mating flight. The fertilized females will found new colonies of their own and begin a new life cycle.

Types of Nests

There is no such thing as a typical ant nest. Whereas some species thrive best in deep shade, others prefer bright sunlight. There are burrowing ants will, some even select a particular type of soil in which to tunnel. Still other types of ants erect mounds of various materials at hand. The home of Lasius flavus is a little grassy mound in a limestone grassland, and Formica rufa is most happy in a three-foot high pile of pine needles in a coniferous forest. An American army ants do not build a nest after a day on the march; rather, they bivouac by arranging a cluster of worker ants over the queen and her brood. This cluster may hang from a branch or fill a hollow log. (The termite, whose giant hills are a feature of the landscape in parts of Africa and South America, are not true ants.)

Many tropical species nest above ground in the crevices of plants or in hollow stems, but Crematogaster ledouxi builds a carton-nest of chewed wood and soil carried high up a tree and into the forest canopy. In the Alps, some species build nests in the rosettes of alpine plants, sometimes thatching a roof out of nearby dried plant remains. In Australia, Oecophylla sew leaves together (see cover illustration) to produce a leaf-bag nest, using silk produced by their own larvae for “thread.”

The leaf-cutter ant Atta sexdens in the Americas constructs large, complex nests. In 1955, one such nest was carefully filled with concrete, revealing 120 metres (130 yards) of 3 cm (1.25") diameter tunnels and hundred fungus chambers, with a volume of some 6.5 litres (1.5 gallons) each. The internal temperature of the nest was a full 15?C (27?F) above soil temperature.

Ants are able to tolerate substantial temperature variations. Formica lugubris, for example, starts out in the spring with an optimal nest temperature of 22?C (72?F), but temperatures may reach 32?C (90?F) by autumn. Most species prefer a nest atmosphere almost saturated with humidity.

Ant-Aphid Symbiosis

Many species of ants husband herds of greenflies and blackflies (aphids), either above ground on young plant stems or underground on roots. What can these sap-sucking aphids supply that the ants would want? Aphids secrete drops of honeydew when stroked by ants. The ants then collect this sugar solution and use it for food.

Is aphid honeydew sufficiently nourishing for the ant? Auclair (1963) found it was a complete range of nutrition: proteins, carbohydrates, fats, and minerals. Moreover, it can be collected quickly, Hertzig found when studying a large nest of Lasius fuliginosus: 6 kilos (13 lbs.) were amassed in 100 days. In many cases the ants tend the aphids within the ant nest, but ants may also visit the aphids on nearby food-plants. Wood ants will forage for over 100 metres (109 yds.) throughout the night, visiting up to 65 species of aphids.

The process of milking begins with careful inspection of the aphid colony, which leads to the selection of a suitable “cow.” The ant then repeatedly strokes the abdomen of the aphid with its antennae. A droplet of honeydew is thus coaxed out of the anal aperture for the ant to take. In some species of aphids, the droplet is held by a ring of hairs until the ant has collected the entire droplet (see cover illustration). In other species, a partially consumed droplet may be retracted and extruded again later when another ant strokes the aphid's abdomen. If, after a while, no other worker ant comes to collect it, the surplus honeydew is flicked away by the aphid using its third pair of thoracic legs.

The symbiotic relationship the ant has with its aphids extends to defence, as well. Aphids can repel unwelcome visitors, such as the larvae of the ladybird beetle, by using the paired tubes that project above the aphid's abdomen to daub them with a waxy solution. And the worker ants sometimes afford protection to the aphids by carrying them to safety when predators threaten.

A Harvest of Fungi

As Agur observed almost three millennia ago: “The ants are a people not strong, yet they prepare their food in the summer” (Proverbs 30:25). Consider Messor structor, for example. This species opens seeds and chews them to a starch and saliva paste, with several ants working on single grain at the same time.

Many ant colonies deliberately cultivate fungus within their nests. They collect circular pieces of leaves, cut with their jaws while turning on one leg in compass-like fashion. The leaves form compost that is inoculated by the queen with fungal fragments from her previous nest, carried away in a pocket beneath her jaws. The fungus garden is fertilized by ant faeces, and the vegetable portion, the fungal mycelium, are fed to the larvae by workers.

Anatomy of an Ant

Like other insects, ants are covered with a skin, or cuticle, that is hard in some places and soft in others. Adjacent hard parts are articulated with a flexible soft membrane.

There are three basic parts to the body of an ant and each carries an important survival feature: the head has the mouth, the legs are attached to the thorax, and the abdomen houses the sting. The mouth-parts consist of a set of tiny protrusions from the head. They include a pair of mandibles that perform many tasks, such as carrying prey, cutting up and manipulating food, excavating passages in the soil, and transporting eggs and larvae about the nest. The legs are arranged in three pairs on the middle portion of the body. Each leg has nine joints, with two claws and an adhesive pad (arolium) at the terminus. The fourth joint (tibia) carries a spur (strigil), used for cleaning the antennae and the other legs. The sting, protruding from the rear of the abdomen, secretes poisonous formic acid, which can be sprayed onto, or injected into, an enemy.

Sensing the Environment

The simplest sense organ possessed by the ant is the hair. Some hairs detect chemicals, and therefore correspond to the senses of taste and smell in man. Experiments with various sugar show that preferences vary: Manica rubida will eat only seven different sugars; Myrmica rubra eagerly devours twelve. The organs responding to these carbohydrates are found in the antennae.

Some propioceptor hairs indicate the positions of the joints by the degree of bending experience. Others set in the cuticle register the physical stresses on the insect that result from deformations of the skin, serving as a warning system to prevent injury from the use of excessive force.

Chordotonal (vibration-sensitive) organs in the blood space of the tibia of each leg contain cells that respond to ground vibrations. Camponotus ligniperdus can detect vibrations between 100 and 3,000 cycles per second and changes in acceleration from 0.2 to 0.7 g (1.95 m/s² to 6.83 m/s²; or 6.4 ft./s² to 22.4 ft./s²).

Adult ants have two types of eyes: a compound pair, placed towards the side of the head, and three simple ocelli on the upper surface of the head. The compound eye is composed of many facets, more or less hexagonal in shape. Each overlies an ommatidium (a radial element), which registers a small portion of the ant's field of view. The total picture for the ant is one of light and dark dots. The more numerous the ommatidia, the more detailed the picture. The maximum degree of resolution, however, is limited by the minimum size of individual ommatidia, which in turn is determined by the maximum wavelength of light to be processed. The visual ability of different types of ants varies greatly. Some rely little on their eyes to function: the driver (army) ant, Eciton burchelli, has large, single-facet eyes that allow for only limited visual capability; a few species of the genus Dorylus are actually blind.

Navigation

The Italian zoologist, Felix Santschi (1911), observed that desert ants in North Africa followed a straight course across barren sand dunes that were totally devoid of landmarks. He suspected they were using the sun to maintain their bearings. His hypothesis was verified when he used a mirror to create a false “sun” in a contrived position above the ants for them to use in navigation. As expected, the ants altered their course the same number of degrees the angle of the mirror's reflected light differed from the sun.

But this means that the ant must be able adjust to the sun's changing position as the day progresses. This is done by fixing the image of the sun in one eye facet and realigning the body's direction after a fixed interval so that the image of the sun is centred in the next facet. Thus, the ant can pursue a straight course without landmarks. Further studies showed that ants could travel in straight lines even when the sky was overcast. Karl von Frisch of Austria found that ants could detect polarized light. Apparently they can use the pattern of polarization in the sky to navigate the same way they employ the image of the sun.

Using glands in their abdomen, scouts leave a scent behind them when they return to the nest after finding new sources of food. The tunnel of aroma persists for a short time before dispersing. Other workers pick up this trail, follow it, and find the food without having to be led there by the scout. A worker coming across a trail accidentally can determine its “polarity,” enabling the ant to know which direction leads to food and which leads back to the nest.

Different species combine different navigational techniques. Many use gravity detection, especially when the nest is situated higher than the surrounding woodland. Each change in the angle of slope is registered by the foraging ant and used to guide it back to the nest again. Various experiments have demonstrated that most ants check their bearings with different methods when following a well-used path. This may be necessary in view of possible interference by other animals crossing their trails.

Ants Created, Not Evolved

The theory of evolution says that the ant developed from something simpler and less specialized. This would have required an increase in genetic information, something which cannot arise spontaneously. That the information needed to form these remarkable creatures even exists speaks of input from an incredibly intelligent Source at the time of their creation. The complex parts and behaviour patterns of the ant are controlled by processes invested with a considerable amount of information. It is easy to see that anything partially evolved in the ant - an eye, a jaw, or a navigational system - would be non-functional and an evolutionary hindrance to be discarded. The fossil record shows that ants have been ants as far back as we know.

Similarly, there is no evidence their symbiotic relationship with aphids has evolved. It is the same today as it was when ancient ants were fossilized - nothing has changed. The Konigsberg fossil collection of over eleven thousand ant specimens in amber contains several examples of ants preserved in the act of milking their aphid cows. (Apparently ants, like men, were going about their usual business when the Flood came and destroyed them all - Luke 17:27.)

The ants survive as a community. It is difficult to imagine how such interdependence of the queen and worker ants could have evolved. How did they survive before they developed this interdependence? No, it is far more reasonable to conclude that the jobs of the workers, the queen, and the mating males were preordained. Each has a different set of instincts generated by genetic information that must have been prepared by a supremely intelligent Creator. When the female worker provides her supplies in the summer and gathers her food in the harvest, she is driven, not by a captain, an overseer, or a ruler, but by a set of instincts instilled by Jehovah Jireh, the Providing Creator.