What are termites?

Termites are incredible, small insects that have mastered cooperation allowing them to achieve great things, such as building skyscrapers, hollowing huge trees, moving amazing amounts of soil and of course, eating your house.

Most people are comfortable that they know what an ant is, but hardly anyone seems sure they know what makes a termite a termite. Termites are not ants and certainly not white ants. That's a really sloppy term, please don't use it. They are most closely related to the cockroaches, and so are very different to ants.
Ants share their insect order with bees and wasps (the Hymenoptera). Termites belong to their own insect order (the Isoptera) and have several clear and obvious differences which make it fairly simple to tell them from apart.

Termites belong to the Order Isoptera:

(Pronounced Eye-sop-terr-a) , the termites, from the Greek, Iso meaning equal and pteron, meaning wing. The name refers to the wings of the reproductive caste, which isn't very helpful as most termites are plain workers that never get to grow wings. There are two pairs of wings, with the front pair the same size as the hind pair. The name termite comes from the Latin word for woodworm.

Description:

Small, pale, soft-bodied social insects living in a nest or colony system. Primarily cellulose feeding. Divided into castes, the most numerous caste are relatively undifferentiated and perform much of the colony work, there is a specialised soldier caste with head and jaw structures differentiated with stronger features and often mouthparts more suited to defence than feeding. The reproductive caste, known as alates (winged ones) are produced when nymphs mature to develop wings and a generally darker colouring. Metamorphosis is gradual (no pupal stage)

Head rounded, eyes generally absent except in the reproductive caste, antennae beaded, wings absent except in reproductive caste. Chewing mouthparts. Wings deciduous, shed shortly after nuptial flight through breakage at a suture near point of attachment (hence de-alate), leaving small scales which persist. Termites are weak fliers, flights occur only under favourable conditions: nearly still air, high humidity and with falling barometric pressure indicating a likelihood of following rain. No constriction of the abdomen (as in ants, bees and wasps). Here's a similar description at the University of Delaware

Termites also behave in ways that makes them easy to identify. For a start, nearly every type live completely in the dark (except when building or when the winged ones are flying), so you usually only see them when something is broken or open. Once exposed, they will try to follow their scent trails home. If these are broken they just wander around looking lost or squeeze into any gap they can find.

Most species of termites have what is called a soldier caste. These grow strong heads, often much darker than those of the other termites. Very often, these strong heads also have big jaws. If you can find some of these among you termites, it makes the job of identifying the species much easier. Soldiers may be rare, only a few percent of the population, so look carefully.