The antennae of Lepidoptera appear to be the main organs of smell. Many moth species use pheromones for sexual attraction which they smell with the antennae. Their antennae have a feathery appearance.

female Papilio aegeus, showing clubbbed antennae.

Butterflies in general appear to use sight rather than smell for sexual attraction, so their antennae are different. They have a bulge on the end of each antenna, like a small club.