Ants run much of the terrestrial world as soil turners, channelers of energy, dominatrics of the insect fauna and yet receive only passing mention in textbooks on ecology.
They employ the most complex forms of chemical communication of any animals and their social organization provides an illuminating contrast to that of human beings, but not one biologist in a hundred can describe the life cycle of any species.
Ants are classified as a single family, the Formicidae, within the order Hymenoptera, which also includes the bees, wasps, sawflies, ichneumons (order of parasitic wasps whose larvae feed on other live insect larvae), and similar forms.
Such incidental nest sites can be divided into convenient categories as follows:
- Preformed cavities in live branches and stems, excavated by wood-boring beetles and other insects and then later occupied by ant colonies.
- Cavities in stems and branches that are naturally hollow or contain a pith soft enough to be easily excavated by ants which includes grasses, sedges, composites, and other herbaceous and shrubby plant forms and so a great variety of ants occupy them.
- Natural or preformed cavities in the bark of trees; such as, pine trees in the southern United States that shelter an entire fauna of ant genera that nest adventitiously in the bark.
- Roots of epiphytes or the tangled root systems of orchids, gesneriads (mostly tropical herbs or shrubs), and other tropical epiphytes are ideal nest sites for ants.
- Galls (abnormal swelling of plant tissue) formed by cynipid wasp larvae, or Cynipidae, a family of gall wasps, hymenopteran insects in the super-family Cynipoidea that produce galls on oaks, which have been observed in Europe and North America.
- Earthen or carton nests constructed vertically against the sunken portions of tree trunks by a few ant species in the New World tropics because the trees provide a partial wall of solid wood which provides some protection for the ant colonies.
None of these diverse structures appears to be "designed" to accommodate ant colonies and all of them are ordinary anatomical features of the plants that the ants exploit, apparently in a unilateral manner.
In contrast, the domatia do appear to serve as ant nests because they are featured by cavities that form independently of the ants.
So, it is adventitious when roots and tubercles absorb nutrients from waste material carried onto the cavities, and even holes or thin windows of tissue through which ants can more conveniently enter and leave their colonies are essentially provided naturally by the plants, but not to entice ants as with the domatia.
- The head
- The thorax or mid-section.
- The abdomen or gastor.
Three pairs of legs are attached to the thorax, and like all insects, ant bodies are encased in a hard, shell-like covering or exoskeleton and their legs are jointed.
The thorax can be broken down into two major parts: the alitrunk, which contains the legs and wings, and the petiole, which is found directly anterior to the gastor and is found only in ants.
Ants have mandibles (jaws) which are of varied structures. These varied structures provide for a plethora of functions ranging from grasping, tearing, cutting and other special tasks.
Most ants have a stinger at the end of the gastor. Some ants can release this stinger similar to the way honeybees do it. The stinger is only found in female ants and is a modified ovipositor (egg laying organ).
Ants have compound eyes which have not been shown to effect their behavior, although some ants seem to be able to detect movements. They have very sensitive antennae that are used for a wide array of communication.
Nearly all ants have a unique gland found on the petiole called the metapleural gland. Most importantly, this gland has been shown to contain antibacterial and antifungal chemicals which are essential for survival in the humid, dark nests in the ground or rotting vegetation.
This gland secretes an antiseptic substance that at times acts as a repellent to attacking organisms. It is also thought that the metapleural gland releases pheromones for communication.
Their varied mandibles are an irreplaceable tool for accomplishing the jobs necessary for the multiple behaviors displayed by various individuals of colonies.
The metapleural gland excretes antifungal and antibacterial materials that ants spread throughout their colonies through their wanderings. This protects their brood and their food supplies in the humid underground environment.
Ant colonies can have single or multiple queens. The number of queens in multiple queen colonies varies by species, ranging from a few queens to nearly half the population in a colony.
Depending on the ant species, queens may live from months to years.
2. Males, that serve one purpose which is to mate or breed with the queen: In the ant caste, males typically die soon after mating or are forced to leave the colony and are normally alive solely during the colony's reproductive stage or period. 3. Workers, which are sterile, wingless females form the main members of the colony: In the ant caste, the workers perform the tasks necessary for the survival and growth of the colony; such as, foraging for or finding food, caring for the brood (eggs, larvae, plus the queen), and excavating or enlarging the nest."Epiphytes" are plants, such as a tropical orchid or a staghorn fern, that grows on another plant upon which it depends for mechanical support but not for nutrients. They are also called aerophytes or "air plants".
One of the most complex mutualisms between plants and ants is the ant garden
To qualify as a true ant garden, the plants must benefit from the ant associations which is an aggregate of epipytes assembled by ants.
The ants bring the seeds of the epiphytes into their carton nests and as the plants grow, nourished by the carton and detritus brought by the ants, their roots become part of the framework of the ant nests.
The ants also feed on the fruit pulp, the elaiosomes (food bodies) of the seeds, and the secretions of the extra-floral nectaries.
- Monomorphic, all the same size.
- Dimorphic, of two sizes.
- Polymorphic, more than two sizes.
Workers divide labor, so some leave the nest to find food while most of them stay in the nest to take care of all of the other tasks which need to be done.
The Azteca ants feed off protein-rich secretions, necessary in their diet, that are produced by special glands at the base of the leaves.
Azteca ants do not sting, but they do bite, and will fiercely protect the tree from potential dangers, for example, they attack other insects that land on the tree and drive them away.
They will cut and kill any vines that begin to climb up the tree, whereas many other trees in the rain forest will be covered in epiphytes or dripping with vines, cecropia trees are generally epiphyte-free and vine-free.
These actions of the Azteca ants allow the cecropia tree to stay healthy, grow as fast as possible, and successfully compete with other trees for limited sunlight. In return, the tree provides the protecting ant with a place to live and a source of food.