Termites are a group of detritophagous eusocial insects which consume a variety of decaying plant material, generally in the form of wood, leaf litter, and soil humus.

Similarly to ants and some bees and wasps from the separate order Hymenoptera, most termites have an analogous "worker" and "soldier" caste system consisting of mostly sterile individuals which are physically and behaviorally distinct.

As early as 1934 suggestions were made that they were closely related to wood-eating cockroaches (genus Cryptocercus, the woodroach) based on the similarity of their symbiotic gut flagellates.

[20] In 2008 DNA analysis from 16S rRNA sequences[21] supported the position of termites being nested within the evolutionary tree containing the order Blattodea, which included the cockroaches.

[31][32][33] Possible evidence of a Jurassic origin is the assumption that the extinct mammaliaform Fruitafossor from Morrison Formation consumed termites, judging from its morphological similarity to modern termite-eating mammals.

The fontanelle connects to the frontal gland, a novel organ unique to Neoisopteran termites which evolved to excrete an array of defensive chemicals and secretions, and so is typically most developed in the soldier caste.

[52] Cellulose digestion in the family Termitidae has co-evolved with bacterial gut microbiota[53] and many taxa have evolved additional symbiotic relationships such as with the fungus Termitomyces; in contrast, basal Neoisopterans and all other Euisoptera have flagellates and prokaryotes in their hindguts.

As a result the caste system of termites consists mostly of neotenous or juvenile individuals that undertake the most labor in the colony, which is in contrast to the eusocial Hymenoptera where work is strictly undertaken by the adults.

In these basal taxa, the immatures are able to go through progressive (nymph-to-imago), regressive (winged-to-wingless) and stationary (size increase, remains wingless) molts, which typically indicates the developmental trajectory an individual follows.

[77][75] There are three main castes which are discussed below: Worker termites undertake the most labor within the colony, being responsible for foraging, food storage, and brood and nest maintenance.

Pseudergates sensu stricto are individuals which arise from the linear developmental pathway that have regressively molted and lost their wing buds, and are regarded as totipotent immatures.

Pseudergates sensu lato, otherwise known as false workers, are most represented in basal lineages (Kalotermitidae, Archotermopsidae, Hodotermopsidae, Serritermitidae) and closely resemble true workers in which they also perform most of the work and are similarly altruistic, however differ in developing from the linear developmental pathway where they exist in a stationary molt; i.e they have halted development before the growth of wing buds, and are regarded as pluripotent immatures.

[81][82] Fontanelles, simple holes in the forehead that lead to a gland which exudes defensive secretions, are a feature of the clade Neoisoptera and are present in all extant taxa such as Rhinotermitidae.

[88] The primary reproductive caste of a colony consists of the fertile adult (imago) female and male individuals, colloquially known as the queen and king.

[78][89] Depending on the species, the queen starts producing reproductive alates at a certain time of the year, and huge swarms emerge from the colony when nuptial flight begins.

[94][74] Larvae, which are defined as early nymph instars with absent wing buds, exhibit the highest developmental potentiality and are able to molt into Alates, Soldiers, Neotenics, or Workers.

[101] The abdomen increases the queen's body length to several times more than before mating and reduces her ability to move freely; attendant workers provide assistance.

[121] Despite primarily consuming decaying plant material as a group, many termite species have been observed to opportunistically feed on dead animals to supplement their dietary needs.

[140][141][142] Other predators include aardvarks, aardwolves, anteaters, bats, bears, bilbies, many birds, echidnas, foxes, galagos, numbats, mice and pangolins.

[149][150] Paltothyreus tarsatus is another termite-raiding species, with each individual stacking as many termites as possible in its mandibles before returning home, all the while recruiting additional nestmates to the raiding site through chemical trails.

[152][153] Other ants, including Acanthostichus, Camponotus, Crematogaster, Cylindromyrmex, Leptogenys, Odontomachus, Ophthalmopone, Pachycondyla, Rhytidoponera, Solenopsis and Wasmannia, also prey on termites.

[82] The pantropical subfamily Nasutitermitinae has a specialised caste of soldiers, known as nasutes, that have the ability to exude noxious liquids through a horn-like frontal projection that they use for defence.

[197] The soldiers of the neotropical termite family Serritermitidae have a defence strategy which involves front gland autothysis, with the body rupturing between the head and abdomen.

A Brazilian study investigated the termite assemblages of three sites of Caatinga under different levels of anthropogenic disturbance in the semi-arid region of northeastern Brazil were sampled using 65 x 2 m transects.

[236] Drywood termites thrive in warm climates, and human activities can enable them to invade homes since they can be transported through contaminated goods, containers and ships.

[255][256] Termite mounds are the main sources of soil consumption (geophagy) in many countries including Kenya, Tanzania, Zambia, Zimbabwe and South Africa.

[263] In South America, cultivated plants such as eucalyptus, upland rice and sugarcane can be severely damaged by termite infestations, with attacks on leaves, roots and woody tissue.

One of the few that do, the Zoo Basel in Switzerland, has two thriving Macrotermes bellicosus populations – resulting in an event very rare in captivity: the mass migrations of young flying termites.

This happened in September 2008, when thousands of male termites left their mound each night, died, and covered the floors and water pits of the house holding their exhibit.

[274] Termites are widely used in traditional popular medicine; they are used as treatments for diseases and other conditions such as asthma, bronchitis, hoarseness, influenza, sinusitis, tonsillitis and whooping cough.