Eyes Insects have two large compound eyes that consist of thousands of tiny lenses shaped like honeycomb cells. These eyes are usually large and located on the sides of the insect's head. Sound Many insects can emit sounds by rubbing their appendages together or vibrating a membrane. The life cycles of insects usually involve a process called metamorphosis, a change from one life form to another. Frogs, toads and salamanders also undergo this big change.
Some insects undergo incomplete metamorphosis.
As the insect matures, it increases in size and develops reproductive organs and wings. For most species, the immature insect, or nymph, looks similar to the adult. However, some nymphs are aquatic and do not resemble their terrestrial adult forms. Examples of these aquatic insects are dragonflies and mayflies. Other insects undergo a major change in their forms as they grow in a four-stage change called complete metamorphosis.