Butterflies and caterpillars are different forms of the same insect. In the process of metamorphosis, the egg hatch to form a larva or a caterpillar. This is the feeding stage, in which the larva feeds and grows. At some stage, it undergoes another phase – the pupa, which is the non-feeding stage. At this stage the insect starts changing its form inside the pupa and finally a fully-grown butterfly with wings is formed. The butterfly has wings, which are actually appendages of the cuticle.
- Simply because wings are hidden in the genes of caterpillars that comes out as time flies.