SOCIAL ANIMALS – MEANING, CHARACTERISTICS, IMPORTANCE & LIFE HISTORY
Table of Contents
Social animals are those in which individuals of the same species live together cooperatively in organized communities known as societies (colonies). Examples of social animals are: social insects (like termites, honey bees or wasps, ants etc), wolves, foxes, baboons etc.
Characteristics of Social Insects
- They live together
- They display division of labour
- They show distinct castes
- Members communicate with one another within the colony.
Habitats of termites: They are found living together in large communities in nest which may be tunnels in dead wood or ant hills (termitaria).
Note- Termites are blind: they communicate through touch and smell.
Castes of termites:
They have three castes: The reproductive, soldiers, workers.
- The reproductive are of three types: king, queen and winged reproductive. The king has no wing, is smaller than the queen and it fertilizes the queen. The queen has a small head, small thorase and large abdomen. It is the largest of all the castes. Only one queen at a time is found in a colony. The queen lays eggs. The winged reproductive are fertile and are potential kings and queens of new colonies.
- The soldiers are sterile, wingless and blind. They have big heads with stony maxillae and mandibles. Soldiers are of two types: (i) The mandibulate soldiers with strong mandibles and (ii) Nasute soldiers with projective mouth paths. The soldiers defend the colony against enemies.
- The workers are wingless, blind, and sterile. They form the majority in the colony and possess well developed mouth paths. They build and repair the termitaria; provide food for colonial members; look after the eggs laid by the queen and baby termites (nymphs).They feed the nymphs and the queen and cultivate fungus gardens.
Life history of termites
Termites exhibit incomplete metamorphosis i.e.
Egg nymph adults
The nymphs develop into soldiers and reproductive. And those which fail to develop become workers. When the winged reproductives are mature, they exhibit nuptial or wedding flight i.e. swarming out from the existing colony to build new ones.
Behavioural adaptation of termites for survival
- They move in groups to ward off their enemies
- They have a wide variety of diet; feeding on both living and dead plants.
- They burrow into the soil or wood to build tunnels for protection against their enemies.
- The habit of feeding on dead members helps to keep the colony clean.
- Their ability of massive production of off springs promotes their survival.
Economic importance of termites
- Termites while building their tunnels help in loosening and mixing the soil.
- They decompose wooden materials as they feed.
- They add humus to the soil through their decomposition activities.
- They act as good source of protein and fat.
- The ant hill clay can be used to build the surface of tennis court.
Habitat of Honey bees – These are social insects living in hives made up of chambers or cell.
Castes of honey bees
The bee colony has 3 castes, namely:
- The drone (in hundreds per colony)
- The queen (only in 1 per colony)
- The workers (in thousand per colony)
- The drone is the winged with shorter abdomen than the queen but bigger than the workers. The drone mates with the queen during the nuptial flight after which it dies.
- The queen is a fertile female, winged and much bigger than the workers. It is fed with royal jelly and lays egg.
- The worker is a sterile female, winged and is smaller than the queen or drone. It possesses eyes and a sting. Also with modified mouth paths for collecting nectar and building the hive. The workers legs are also modified for collecting pollen grains from flowers. The workers perform a special dance called rail wagging as it locates a food source. The workers secrete wax for building the hive, ventilate the hive and clean the cells, guard the hive, make honey from nectar and pollens and feed the larvae with royal jelly or honey.
Economic importance of honey bees
- They help to pollinate flowers.
- They produce honey which has high nutritive and medicinal value.