Identify a Butterfly or Moth

Butterfly or moth? How to tell

There's no single rule, but a few clues usually settle it:

• Antennae - butterflies have thin antennae with a club at the tip; moth antennae are feathery or taper to a point
• Resting wings - butterflies usually fold their wings upright over their back; many moths rest with their wings flat or tented
• Time of day - most butterflies fly by day and most moths at night, though plenty of moths fly by day
• Body - moths are often stouter and fuzzier

Famous look-alikes

Even experienced gardeners mix these up:

• Monarch vs viceroy - the viceroy is smaller and has a black line curving across each hindwing
• Painted lady vs American lady - the American lady has two large eyespots under each hindwing; the painted lady has four or five small ones
• Eastern tiger swallowtail vs giant swallowtail - tigers are yellow with black stripes; giants are mostly dark with bold yellow bands
• Cabbage white vs other whites - the cabbage white has one or two black spots on each forewing

Caterpillars: look, don't touch

Caterpillars can be identified too, and knowing what you have tells you what it will become. But some have stinging or irritating hairs and spines - including the saddleback, the puss caterpillar and the io moth caterpillar - so photograph caterpillars without handling them, and wash your hands if you've touched one.

Bring more butterflies to your yard

Butterflies need two kinds of plants: nectar flowers for the adults and host plants for their caterpillars. Milkweed is the only host plant for monarch caterpillars, black swallowtails use parsley, dill and fennel, and spicebush swallowtails use spicebush. The results list host plants for your species - plant a few natives, skip the pesticides, and you'll see more of them.

Share your sighting

Your photo can help science. Upload sightings to iNaturalist, where other naturalists help confirm IDs and researchers use the records to track populations and migrations.