Butterflies are insects. A butterfly grows in four steps. The steps are egg, caterpillar, chrysalis, and adult butterfly. A butterfly pupa is called a chrysalis. A cocoon is the silk case a moth caterpillar spins. A baby caterpillar starts by eating its own eggshell. Butterflies fly in the day. Most moths fly at night.

A female monarch lays her eggs. She lays them one at a time. She lays them on milkweed leaves. A monarch egg hatches after a few days. It is usually about four. A monarch caterpillar eats and grows for about two weeks. It does this before it makes a chrysalis. It has thin black tentacles. They are at the front and the back of its body.

Many caterpillars hang upside down. They hang from a button of silk. They do this just before they become a chrysalis. A monarch chrysalis is green. It has tiny gold dots. It is often hard to see. It blends in with its surroundings. A monarch stays inside it for about two weeks.

Monarch caterpillars eat milkweed. Milkweed is poison to most animals. The poison stays in the monarch's body. It makes the monarch taste bad. A monarch has bright colors. They warn birds that it tastes bad. Most swallowtail caterpillars have a hidden smelly gland. It is behind the head. It pops out like an orange fork when the caterpillar is scared. Butterflies and caterpillars are food for birds, lizards, spiders and other animals.

Adult butterflies drink sweet nectar from flowers. They drink with a long tongue called a proboscis. It curls up like a spiral when the butterfly is not drinking. Butterflies sometimes sip from wet mud. They get minerals like salt. Butterflies like flat flowers that grow in clusters. The flowers make a good landing pad.

Some butterflies spend the winter asleep. They sleep as an egg, caterpillar, chrysalis or adult. Monarchs cannot live through cold northern winters. So they fly south. Monarchs east of the Rocky Mountains spend winter in Mexico. Some monarchs fly as far as 3,000 miles. The monarchs that fly to Mexico have never been there before. Yet they find the way.

Words to know

• cocoon: silk case
• proboscis: long tongue
• chrysalis: butterfly pupa

The short version

Butterflies are insects. A butterfly grows in four steps: egg, caterpillar, chrysalis, and adult butterfly. Adult butterflies drink sweet nectar from flowers. Monarch caterpillars eat milkweed leaves. Milkweed is poison to most animals. Monarchs east of the Rocky Mountains spend winter in Mexico.

Quick facts

• Butterflies are insects.
• A butterfly grows in four steps: egg, caterpillar, chrysalis, and adult butterfly.
• Adult butterflies drink sweet nectar from flowers.
• Monarch caterpillars eat milkweed leaves.
• Monarchs east of the Rocky Mountains spend winter in Mexico.