Taxonomists commonly argue over how to define the obvious differences between butterflies and moths. However here are some of the main differences. The most obvious difference is in the feelers (or "antennae"). Butterflies tend to have thin, smooth antennae which are club-shaped at the end. Moths often have feathery antennae which are not club-shaped at the end. The transformation stage differs as well . Most moth caterpillars spin a soft cocoon made of silk whereas butterflies form a hard (or semi-hard) chrysalis.