: Most have large eyes made of many tiny lenses, which are excellent at detecting motion. Major Roles in Nature
To be classified as an insect (class Insecta ), an animal must typically have: The Insects
: Insects have been around for more than 350 million years—longer than dinosaurs or flowering plants. All About Insects | Life Cycle & Metamorphosis : Most have large eyes made of many
Insects are crucial to the planet's health, performing roles that humans often take for granted: leading to their alternate name
: Insects act as nature's janitors, breaking down dead plant and animal matter, which returns vital nutrients to the soil.
: All adult insects have exactly three pairs of legs, leading to their alternate name, "Hexapoda".