Butterfly or moth?

One big family, two rough labels

Butterflies are a small, colourful branch of the moth family tree. Here’s how to tell them apart, most of the time.

Not so different

There is no real scientific difference between butterflies and moths; we split them out of habit. Oxford University Museum of Natural History: Lepidoptera The Australian Museum describes butterflies and skippers as groups of specialised moths. Australian Museum: What are the differences between butterflies and moths?

Worldwide there are five families of butterflies and one of skippers, but 125 families of moths. Australian Museum: What are the differences between butterflies and moths?

The rules of thumb

Rule of thumb: butterflies fly by day, rest with wings held together above the back and have clubbed antennae; moths mostly fly at night, rest with wings flat and have straight or feathery antennae. American Museum of Natural History: Butterfly FAQ

…and the exceptions

Not all moths fly at night: the Cinnabar and Scarlet Tiger fly by day, and some butterflies, such as the Red Admiral, fly at night. Butterfly Conservation: Moth myths Some moths have clubbed antennae too, such as the day-flying burnets. Butterfly Conservation: Moth myths

Moths are not all dull. Tiger moths are almost gaudy, and many dull moths have intricate camouflage patterns. Butterfly Conservation: Moth myths Brightly coloured moths are often day-flyers, or species warning predators that they taste bad. Dull colours hide night-flying moths while they rest by day. Natural History Museum, London: UK moths, nine of the most colourful and distinctive

The most consistent difference

The most consistent difference: nearly all moths have a tiny hook joining the hindwing to the forewing. Butterflies do not. Butterfly Conservation: Moth myths That wing-locking bristle is called a frenulum. Australian Museum: What are the differences between butterflies and moths?

Feathery antennae

The ‘feathery’ antennae of many male moths pick up tiny amounts of scent (pheromones) released by females. Australian Museum: What are the differences between butterflies and moths? Males of giant silkworm moths, with very large feathery antennae, can find females 5 to 6 km (3 to 4 miles) away. Britannica: Lepidoptera (natural history, behaviour and ecology)

Cocoons and chrysalises

Many moth caterpillars spin silk cocoons to pupate in. Many butterfly pupae are not hidden in cocoons at all. Australian Museum: What are the differences between butterflies and moths? Most butterflies don’t spin cocoons: their own body forms the chrysalis. Many hang head-down from a silk pad. Britannica: Lepidoptera (natural history, behaviour and ecology)

Do moths eat clothes?

Of about 2,500 moth species in Britain, only a very few eat clothes, and only fabrics from animals such as wool. Butterfly Conservation: Moth myths More than 90% of moth caterpillars eat plants: leaves, roots, seeds and fruits. Natural History Museum, London: UK moths, nine of the most colourful and distinctive

Can you tell them apart? Try the Butterfly or Moth? game.

Next: scales & senses →