Butterfly Facts
A butterfly is a day-flying insect of the order Lepidoptera with four scale-covered wings, six legs and a pair of antennae that end in a small club. It begins life as an egg, feeds as a caterpillar, transforms inside a chrysalis and emerges as a winged adult that drinks nectar through a coiled straw. This hub gathers our 19 guides to how butterflies live, eat, fly, mate, migrate and survive the winter.
On this page
What is a butterfly?
A butterfly is an insect belonging to the order Lepidoptera, the group of around 160,000 species whose wings are covered in tiny overlapping scales. Butterflies make up roughly 17,500 of those species; the rest are moths. Like every insect it has a head, a thorax and an abdomen, six jointed legs and a pair of antennae. What sets butterflies apart is the combination of four large, often brightly coloured wings, antennae tipped with a club, a habit of flying by day and a life that passes through complete metamorphosis, so that the adult looks nothing like the caterpillar it grew from. The parts of a butterfly guide labels every one of these features, and the butterfly colours guide explains why the wings are so vivid.
Butterflies are grouped into six families: the swallowtails, the whites and sulphurs, the gossamer-winged blues, coppers and hairstreaks, the metalmarks, the brush-footed butterflies and the skippers.
All the butterfly facts guides
Each guide below answers one big question in depth, with photographs of real species and links to their profiles.
The life cycle
Life cycle of a butterfly: the four stages of complete metamorphosis, how long each one lasts and what happens inside the chrysalis.
Butterfly eggs: what the eggs look like, how many a female lays, where she puts them and how long they take to hatch.
Caterpillars: the larva of a butterfly: its body, its moults, what it eats and how it defends itself.
Butterfly pupa: the chrysalis, how it forms, how the adult develops inside it and how to tell a healthy one.
How long butterflies live: lifespans from a few days to nine months, and why the Monarch outlives them all.
How butterflies mate and reproduce: courtship, pairing, how males find females and how eggs are fertilised and laid.
Food and plants
What butterflies eat: nectar, sap, rotting fruit, minerals from mud and dung, and how the proboscis works.
Butterfly host plants: the plants each caterpillar needs, why females are so choosy and what to grow for a butterfly garden.
Seasons, homes and journeys
The butterfly season: when butterflies appear, when they peak and which species fly first and last each year.
Where butterflies go in the winter: hibernation as egg, caterpillar, chrysalis or adult, and which species migrate instead.
Butterfly migration: the Monarch's journey to Mexico, the Painted Lady's African circuit and how butterflies find their way.
Butterfly habitat: meadows, forests, deserts, mountains and gardens, and what each species needs from its home.
Body, colour and flight
Parts of a butterfly: head, thorax, abdomen, wings, legs, antennae, eyes and proboscis, labelled and explained.
Why butterflies are so colourful: pigments, structural colour, warning colours, camouflage and mimicry.
Butterflies with eyes on their wings: what eyespots are for and the species that show them best.
How butterflies fly: the flight mechanism, wing beats, speed, altitude and why the flight looks so erratic.
Behaviour and safety
What butterflies do: pollination, their place in the food chain and their value as indicators of a healthy environment.
What eats butterflies: birds, lizards, spiders, wasps and the other predators of every life stage.
Do butterflies bite?: why they cannot bite or sting, and whether any caterpillar can hurt you.
Quick butterfly facts
- Butterflies taste with their feet: sensors on the legs tell a female whether the leaf she has landed on is the right host plant for her eggs.
- An adult cannot chew. It drinks through a proboscis, a tube that stays coiled under the head until it is unrolled into a flower.
- Most butterflies need a body temperature of about 30 °C (86 °F) to fly, which is why they bask with open wings on cool mornings.
- A butterfly's wings are transparent; the colour comes from thousands of scales, and a few species such as the Glasswing have so few scales that you can see straight through them.
- The Monarch flies up to 4,800 km (3,000 miles) to spend the winter in Mexico, and the Painted Lady completes a round trip of some 15,000 km between Africa and the Arctic over several generations.
- The largest butterfly, Queen Alexandra's Birdwing, spans up to 25 cm; the smallest blues span barely more than a centimetre.
- A group of butterflies is called a kaleidoscope, a swarm or a flutter.
- Butterflies have been on Earth for at least 56 million years.
Butterfly or moth?
Butterflies and moths belong to the same order, and the line between them is blurry. The most reliable difference is the antennae: a butterfly's end in a club or hook, while a moth's are feathery, tapered or thread-like. Butterflies usually fly by day and rest with their wings closed over the back; most moths fly by night and rest with the wings flat or folded like a tent, but there are day-flying moths and dusk-flying butterflies. Butterflies form a hard chrysalis, whereas many moths spin a silk cocoon around the pupa. Moths also tend to be stouter and furrier. The butterfly pupa guide shows the chrysalis in detail.
Why butterflies matter
Butterflies pollinate wildflowers and crops, feed birds, lizards and spiders at every stage of their lives, and, because they respond so quickly to changes in weather, plants and land use, serve as living indicators of the health of a landscape. Long-running counts in Europe and North America show that many once-common species have declined steeply since the 1970s through habitat loss, pesticides and climate change, which is why planting native host plants and nectar flowers is one of the simplest ways anyone can help wildlife.
How to use this site
The facts guides explain how butterflies work; the rest of the site tells you which butterfly you are looking at. Every species profile has photographs of the egg, caterpillar, chrysalis and adult, the host plants, the range, the flight season and the look-alikes. The regional pages list the butterflies of each place by family: there is a page for every state under butterflies in the United States, and one for each of more than 80 nations under butterflies of the world. If you have a photograph and no name, start with the region, narrow it down to a family by shape and size, then compare the closest profiles.
Quick links to the guides
- Life Cycle of a Butterfly
- Butterfly Eggs
- Caterpillars (Larvae of a Butterfly)
- Butterfly Pupa (Chrysalis)
- Butterfly Host Plants
- When is the Butterfly Season
- Where do Butterflies go in the Winter
- Why are Butterflies So Colorful
- Why do Some Butterfly Species have Eyes on Wings
- Flying Mechanism of Butterflies
- Butterfly Habitat
- What Predators Eat Butterflies
- How do Butterflies Mate and Reproduce
- What do Butterflies do to Help the Environment
Frequently asked questions about butterflies
What are the four stages of a butterfly's life cycle?
The four stages are the egg, the caterpillar (larva), the chrysalis (pupa) and the adult butterfly. This is complete metamorphosis: the caterpillar does nothing but eat and grow, the chrysalis rebuilds its body, and the winged adult mates and lays eggs. Depending on the species and the climate, a full cycle takes from about a month to a year.
Is a butterfly an insect?
Yes. A butterfly is an insect in the order Lepidoptera, which it shares with the moths. Like all insects it has a body divided into head, thorax and abdomen, six jointed legs, a pair of antennae and an external skeleton, and it belongs to the animal kingdom. Around 17,500 butterfly species are known worldwide, in six families.
How long does a butterfly live?
Most adult butterflies live for two to four weeks. Small species may survive only a few days, while butterflies that hibernate as adults, such as the Mourning Cloak, and the migrating generation of the Monarch can live for eight or nine months. Counting the egg, caterpillar and chrysalis stages, the whole life of a butterfly usually lasts between one month and a year.
What do butterflies eat?
Adult butterflies drink liquids, mainly flower nectar, which they sip through a long coiled tube called a proboscis. Many also take tree sap, juice from rotting fruit and minerals from mud, dung and even sweat. They cannot chew solid food. Caterpillars are the eating stage and feed on the leaves of their particular host plants.
Where do butterflies go in the winter?
Butterflies survive winter in two ways. A few species, most famously the Monarch, migrate to warmer places, but most stay put and pass the cold months in a dormant state called diapause as an egg, a caterpillar, a chrysalis or, in species such as the Mourning Cloak and Peacock, as a hibernating adult tucked into bark, a woodpile or a shed.
How can you tell a butterfly from a moth?
Look at the antennae: a butterfly's end in a small club, while a moth's are feathery, tapered or thread-like. Butterflies usually fly by day and rest with their wings held together above the body, and they form a bare chrysalis. Most moths fly at night, rest with the wings flat and pupate inside a silk cocoon, and they tend to have plumper, furrier bodies.
Why do butterflies fly in such a zigzag way?
The erratic, fluttering flight of a butterfly makes it hard for birds to predict where it will be next and grab it. Large, flexible wings also let butterflies change direction sharply and glide, and different species fly differently: skippers dart, swallowtails glide and flap, and the Monarch soars on thermals for hours during migration.
Are the spots on a butterfly's wings real eyes?
No. The round markings on the wings of Peacocks, Buckeyes and owl butterflies are eyespots, patterns of scales that imitate eyes. They startle or confuse predators, and spots near the wing edge draw a bird's peck away from the body, so the butterfly escapes with a torn wing. The real eyes are the two large compound eyes on the head.
What is a group of butterflies called?
A group of butterflies is most often called a kaleidoscope; a swarm, a flutter and a rabble are also used. When butterflies gather to drink minerals from damp ground the behaviour is called puddling. Few species are truly social: Monarchs cluster in their thousands at winter roosts, but most butterflies feed and fly alone.
Can a butterfly bite or sting?
No. Butterflies have no jaws, teeth or stinger and cannot bite or sting a person; their only mouthpart is a soft straw-like proboscis for drinking. A butterfly that lands on your skin is usually after the salt in your sweat. A handful of caterpillars carry irritating hairs or spines, but the adult butterflies are completely harmless.
Published February 18, 2020 · Last updated September 21, 2026