ANTS (Hymenoptera)
Ants are cousins of honeybees as they belong to the same order Hymenoptera, but while the honeybees are diurnal and sleep in the night, ants are busy working day and night. Ants have no wings, except in winged sexual forms that are produced in breeding season.
SOCIAL STRUCTURE
Ants have the highest developed social system, next only to man, with no apparent conflict seen in the society. A colony may have few thousand to over 500,000 individuals. The nests are built in various designs and are called formicaria. Like honeybees, they have polyethism, which means castes are specialized to carry out specialized duties in the colony.
For example, the queen has large abdomen to lay a lot of eggs (2-3 million in a year), males fertilize her, workers have broad, sharp mandibles for cutting and chewing and the soldiers have large head that bears sharp dagger-like mandibles for fighting. Workers and soldiers are sterile females. Soldiers of the door-keeping ant (Colobopsis etiolata) have such gigantic heads that they use it for blocking the entrance of the nest. They are extremely powerful creatures that can easily lift 20 times their own weight.
Ants have poor eyesight and are deaf but have a highly sophisticated chemical language for communication. They possess glands that secrete pheromones or messengers of chemical language that is perceived by one of antennae or feelers located on head. They trade food, glandular secretions and enzymes, which is called tropholaxis.
The course of migrating ant columns is directed by the chemical trail left by the scouts and constant body contacts among the following foragers. Sometimes if their chemical trail is washed away by rain, they are doomed to follow each other’s trail in circular tracks with eccentrically high speed.
Most species excavate nests in the ground or wood but some construct suspended nests on trees made of earth, carton, wax or silk, while some, like safari ants, do not build nests at all. Desert ants build crater-like nests or mounds in which they are able to maintain temperature much below the outside heat of deserts. However, workers of the colony are allowed entry after they gently tap on the head of doorkeeper soldier. The tropical ant Oecophylla makes nest by webbing the leaves together with silken thread that is produced by their larvae. While many workers hold the leaves close together, some workers hold the larvae in their mandibles and use them like living thread balls to spin web to attach the leaves together.
Almost all ants store food for the lean periods but in the Australian honey pot ants (Myrmecocystus hortideorum and Camponotus inflatus), also called honey barrels, some members are specially modified to store honey. Their bodies are sac-like and appendages modified as hooks. They store honey in their enormously large abdomen and hang from the ceiling and perform no other apparent function. These casts are called Repletes which are specially adapted to store honey stolen by foragers from the bee hives.
Ants are also known to cultivate grasses and harvest and store their seeds. Some species raid the nests of other species of ants and rob them of stored food and keep their members as slaves in their own nests.