Butterfly & Moth Differences

In addition to the color and behavioral differences often used to differentiate 'moths' from 'butterflies', the antennae may also be used to differentiate the two groups. Butterfly antennae each usually terminate in a knob-like swelling not normally found on the more whip-like or feathery antennae of the moth.

Sources

Butterflies of North America, USGS
Photos: Courtesy of S.P. Johnson

Cloudless Sulphur Butterfly Cloudless Sulphur Butterfly
Tiger Moth Tiger Moth
Tawny Emperor Tawny Emperor