Uniramia is the largest class of animals on Earth, comprising of at least three fourths the animals on the planet. It includes insects, millipedes, centipedes, etc. Uniramians are characterized by having uniramous, or single branched, appendages. The majority of uniramians are terrestrial, although a few species are aquatic.

Insects are the most numerous group of animals on the planet. They have several common features. Most have a body with the three main sections: the head, which usually has a pair of antennae as well as eyes; the thorax, which has three pairs of legs; and the abdomen, which usually has two pairs of wings.