Caterpillars eat plants while most butterflies drink the nectar of flowers. Those that live for several months also eat pollen and other foods. This requires a change in how they eat for the caterpillar has a mouth to bit off pieces of leaves and push it into his body, while butterflies have a long slender sucking tube. When the tube is not in use it is coiled up like a delicate watch spring. By uncoiling the tube butterflies probe deep into the flowers and suck up the nectar.
Caterpillars crawl to move around.
Their body consists of a head followed by 12 or 13 segments. These true legs are usually hard, jointed, and tipped with tiny claws. To support the rest of its long body, the caterpillar also has from two to five pairs of soft, thick prolegs that disappear when it changes into a moth or butterfly. Butterflies have three legs and three body sections and they fly. Their wings and certain portions of their bodies are covered with a fine dust.