Insects and Their Life Cycles

Grade 1 · Science · Study Guide

Learn what makes an insect and how insects change as they grow.

Insects are the most common animals on Earth. A bee, an ant, a butterfly, and a grasshopper are all insects. How can you tell if an animal is an insect? All insects have six legs and three body parts: the head, the thorax, and the abdomen. Most insects also have wings and antennae.

Insects grow and change in a process called a life cycle. Many insects go through four stages: egg, larva, pupa, and adult. This is called complete metamorphosis.

A butterfly is a great example. First, a butterfly lays tiny eggs on a leaf. The egg hatches into a caterpillar, which is the larva. The caterpillar eats and grows. Then it wraps itself in a chrysalis, which is the pupa stage. Inside the chrysalis, the caterpillar changes completely. Finally, a beautiful butterfly comes out — that is the adult stage.

Some insects, like grasshoppers, go through only three stages: egg, nymph, and adult. A nymph looks like a small adult without wings. This is called incomplete metamorphosis.

Insects are very important. Bees help pollinate flowers so plants can make seeds and fruit. Insects also help break down dead plants and animals, which keeps soil healthy.

Key terms

insect

An animal with six legs, three body parts, and usually wings and antennae

life cycle

The stages an animal goes through from birth to death

metamorphosis

The process of change an insect goes through as it grows

larva

The worm-like young stage of an insect, like a caterpillar

pupa

The resting stage where a larva changes into an adult insect

pollinate

To carry pollen from one flower to another so the plant can make seeds

Flashcards

Insect

Animal with 6 legs, 3 body parts, and usually wings and antennae

Life cycle

The stages an animal goes through from birth to adult

Metamorphosis

The big change an insect goes through as it grows

Egg

The first stage of an insect's life cycle

Larva

The second stage; looks like a worm or caterpillar

Pupa

The resting stage when the larva transforms into an adult

Chrysalis

The protective case around a butterfly pupa

Pollinate

To move pollen between flowers so plants can make seeds

Questions

1. How many legs does an insect have?

   1. Four
   2. Six
   3. Eight
   4. Ten
   Show answer

   Answer: Six

   All insects have exactly six legs — this is one of the main features that identifies an insect.

2. A caterpillar is the larva stage of a butterfly.

   Show answer

   Answer: True

   A caterpillar is the larva stage of a butterfly's life cycle.

3. The four stages of complete metamorphosis are egg, larva, pupa, and ________.

   Show answer

   Answer: adult

   Complete metamorphosis has four stages: egg, larva, pupa, and adult.

4. What are the three body parts of an insect?

   1. Head, wings, legs
   2. Head, thorax, abdomen
   3. Eyes, mouth, antennae
   4. Front, middle, back legs
   Show answer

   Answer: Head, thorax, abdomen

   An insect's body has three parts: the head (eyes and antennae), thorax (wings and legs attach here), and abdomen.

5. Bees help pollinate flowers.

   Show answer

   Answer: True

   Bees are important pollinators — they carry pollen from flower to flower, helping plants make seeds and fruit.

Get a personalized course on Insects and Their Life Cycles built around your child.