The: Insects

: A single pair of "feelers" on the head used for sensing touch, smell, and sometimes sound.

Most insects undergo , a dramatic change in form from birth to adulthood. The Insects

Insects are crucial to the planet's health, performing roles that humans often take for granted: : A single pair of "feelers" on the

: Scientists estimate there are roughly 1.4 billion insects for every human on Earth. and sometimes sound. Most insects undergo

To be classified as an insect (class Insecta ), an animal must typically have:

: They are a critical link in the food chain, providing high-protein meals for birds, reptiles, amphibians, and mammals.

: All adult insects have exactly three pairs of legs, leading to their alternate name, "Hexapoda".