Insect antennae, various mouthparts (mandibles, maxillae, etc.), and posterior pointy bits (cerci) are, in embryological development, modified legs. The primord

Insect antennae, various mouthparts (mandibles, maxillae, etc.), and posterior pointy bits (cerci) are, in embryological development, modified legs. The primordial insect bodyplan is a tube segmented into 10-11 parts, each of which carries a pair of legs. In existing insects, segments may have fused and their legs may be highly specialized. The insect head, for example, is the first several segments fused together. Insect embryology is a source of endless entertainment.[1] [1] https://en.wikipedia.org/wiki/Arthropod_head_problem https://en.wikipedia.org/wiki/Arthropod_head_problem