A female that has flown, mated and is producing eggs, is termed "Queen". Similarly, a male that has flown, mated and remains in promixity to a queen, is termed a "King". These anthropomorphic terms have caused great misunderstanding of colony dynamics. Research using genetic techniques to determine relatedness of colony members is showing that the idea that colonies are headed by a monogamous royal pair is at least sometimes incorrect. Multiple pairs of reproductives within a colony are not uncommon, but for the families Rhinotermitidae and Termitidae, at least, sperm competition does not seem to occur (male genitalia are very simple and the sperm are anucleate), suggesting that only one male (king) generally mates within the colony.

At maturity, a primary queen can lay several thousand eggs a day. In physogastric species, the queen adds an extra set of ovaries with each mould, resulting in a greatly distended abdomen and increased fecundity. The distended abdomen increased her size in some species to as much as 10 centimetres, hundreds of times the original size, effectively immobilizing her. In times where these huge queens must be moved to a new chamber it requires a group effort to move her and hundreds of workers are required to push her. The queen is widely believed to be a primary source of pheromones useful in colony integration. As a reward for attending workers a juice is secreted form queen's posterior for the workers to drink.

The king remains only slightly bigger than an average termite and continues to mate with the queen for life. This is very different from ant societie, which have colonies with only a queen which mates once with the male(s) and stores his gametes for life. Males in ant colonies die immediately after mating, unlike termite male alates, which become kings and live with the queen.

The alate caste, also reffered to as the reproductive caste, are generally the only termites with well-developed eyes (although workers of some harvesting species do have well-developed compund eyes and in other species soldiers with eyes occasionally appear). Immature alates still going through incomplete metamorphosis from a sub-caste in certain species of termites, functioning as functional workers ('pseudergates') and also as potential supplementry reproductives. Supplementaries have the ability to replace a dead primary reproductive and in at least some species several are recruited once a primary queen is lost.

Workers termites undertake the labours of foraging, food storage, brood, nest maintenance and some of the defense effort in certain species. Workers are the main caste in the colony for the digestion of cellulose in food. This is achieved in one of two ways. In all termite families except the Termitidae, there are flagellates (Protista) in the gut that assist in celluose digestion. However, in the Termitidae, which account for approximately 60% of all termite species, the flagellates have been lost and this digestive role is taken up, in part, by a consortium of prokaryotic organisms. This simple story, which has been in Entomology textbooks for decades, is complicated by the finding that all studied termites can produce their own cellulase enzymes, and therefore can digest wood in the absence of thier symbiotic microbes. Our knowledge of the relationships between the microbial and termite parts of their digestion is still rudimentary. What is true in all termite species, however, is that the workers feed the other members of the colony with substances derived form the digestion of plant material, either from the mouth or anus. This process of feeding of one colony member by another is known as trophallaxis, and is one of the keys to the success of the group as it frees the parents from feeding the young, allowing for the group to grow much larger and ensuring that the gut symbionts are transferred from one generation to another.

Termite workers usually have undeveloped eyes and are blind. Despite this limitation, they are able to create elaborate nests and tunnel systems using a combination of soil, chewed wood/ cellulose, salive and faeces.
The soldier caste has anatomical and behavioural specializations, primarily useful against ant attack. The proportion of soldiers within a colony varies both within and between species. Many soldiers have jaws so enlarged that they cannot feed themselves, but instead, like juveniles, are fed by workers. The pan-tropical sub-family Nasutitermitinae (which should probably have the South American species separated) have soldiers with the ability to exude noxious liquids through either a horn-like nozzle (nasus) or simple hole in the head (fontanelle). Fontanelles which exude defensive secretions are also a feature of the family Rhinotermitidae. Many species are readily identified using the characteristics of the soldiers' heads, mandibles, or nasus. Among the drywood termites, a soldier's globular ("phragmotic") head can be used to block their narrow tunnels. Termite soldiers are usually blind, but in some families, soldiers developing from the reproductive line may have at least partly functional eyes.

The specialization of the soldier caste is principally a defence against predation by ants. The wide range of jaw types and phragmotic heads provides methods which effectively block narrow termite tunnels against ant entry. A tunnel-blocking soldier can rebuff attacks from many ants. Usually more soldiers stand by behind the initial soldier so once the first one falls another soldier will take the place. In cases where the intrusion is coming from a breach that is larger than the soldier's head, defence requires special formations where soldiers form a phalanx-like formation around the breach and blindly bite at intruders or shoot toxic glue from the nasus. This formation involves self-sacrifice because once the workers have repaired the breach during fighting, no return is provided, thus leading to the death of all defenders. Another form of self-sacrifice is performed by South-East Asian tar-baby termites (Globitermes sulphureus). The soldiers of this species commit suicide by autothysis - rupturing a large gland just beneath the surface of their cuticle. The thick yellow fluid in the gland becomes very sticky on contact with the air, entangling ants or other insects who are trying to invade the nest.

Termites undergo incomplete metamorphosis, with their freshly hatched young taking the form of tiny termites that grow without significant morphological changes (other than wings and soldier specializations). Some species of termite have dimorphic soldiers (up to three times the size of smaller soldiers). Though their value is unknown, speculation is that they may function as an elite class that defends only the inner tunnels of the mound. Evidence for this is that, even when provoked, these large soldiers do not defend themselves but retreat deeper into the mound. On the other hand, dimorphic soldiers are common in some Australian species of Schedorhinotermes that neither build mounds nor appear to maintain complex nest structures. Some termite taxa are without soldiers; perhaps the best known of these are the Apicotermitinae.

This Article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia Articles "Termite".