Montana Public Radio

Bug Bytes: Moths Vs. Butterflies

May 7, 2019

In this corner, weighing in with approximately 700 different species in the United States … the Butterflies. And in the opposite corner, weighing in with over 15,000 species in the United States … the Moths.

While butterflies get most of the attention, moths dominate the order Lepidoptera (comprised of moths and butterflies) with 90% of the known species. But when looking at an individual, how can you easily tell which is which?

First, look at their antennae. Most butterflies have thin, hair-like antennae with a bulb or club at the tip. Moths, on the other hand, often have comb-like or feathery antennae, or hair-like antennae without the club tip.

Moths tend to have stout and hairy or furry-looking bodies, while butterflies typically have slender and smoother abdomens.

Butterflies frequently fold their wings above their backs when they are perched. Moths usually rest with their wings spread out to their sides.

Both of their wings are covered in scales, but the scales on moth wings tend to be larger, making them look more dense and fluffy.

Butterflies tend to be more colorful, while moths are usually brown, grey, white or black with obscuring patterns of zigzags or swirls which help camouflage them from predators.

And lastly, what time is it? Butterflies are usually seen during the day, while moths are mostly active at night.

But as you pay more and more attention to the differences between moths and butterflies, you’ll soon realize that there are exceptions to everything we just told you.

Identification guidelines can help you determine if you’re seeing a moth or a butterfly, but when it comes to nature, it’s best to err on the safe side and learn to never say “never”.

BugBytes is made possible by the Missoula Butterfly House and Insectarium, and Montana Public Radio. This show is also supported by funding from the Greater Montana Foundation: Encouraging communication on issues, trends and values of importance to Montanans.