---
title: "Animal Life Cycles"
description: "Describe differences in the life cycles of mammals, amphibians, insects, and birds, comparing metamorphosis with direct development"
canonical: https://lightmysky.com/learn/science/animal-life-cycles-mt_A1Xfu5p5KT
source: https://lightmysky.com/learn/science/animal-life-cycles-mt_A1Xfu5p5KT.md
retrieved: 2026-10-19
---

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# Animal Life Cycles

Describe differences in the life cycles of mammals, amphibians, insects, and birds, comparing metamorphosis with direct development

Subject: Science · Area: Ecosystems & Habitats · Ages 9 to 10
Page: https://lightmysky.com/learn/science/animal-life-cycles-mt_A1Xfu5p5KT

## Ready when they can

- Describe the life cycle of a mammal, amphibian, insect, and bird with key stages for each
- Compare metamorphosis (complete change of form) with direct development (gradual growth)
- Identify which groups undergo metamorphosis and which do not

## Lesson: Comparing Animal Life Cycles

You already know that living things grow through stages, and that metamorphosis means a total change of body shape. Now let's line up four animal groups side by side: mammals, birds, amphibians, and insects. Each one starts life differently, and each one reaches adulthood in its own way.

**Example.** Look at a mammal and a bird. A puppy is born already shaped like a tiny dog: four legs, fur, a tail. It just eats, grows, and gets bigger until it's a full-sized dog. A chick hatches from its egg looking like a small, fuzzy bird. It grows feathers and gets bigger, but keeps the same basic shape the whole time. Both are examples of direct development.

*(drawing: A butterfly's metamorphosis: egg, caterpillar, chrysalis, then butterfly.)*

**Example.** Now look at an amphibian. A frog starts as an egg in water. It hatches into a tadpole, which swims and breathes with gills, and looks nothing like a frog. Slowly the tadpole grows legs and loses its tail, becoming a froglet. Finally it becomes a full-grown frog that breathes air and hops on land. Like insects, amphibians go through metamorphosis.

**Tip.** Here's a quick way to tell them apart. If a baby animal looks like a totally different creature and passes through a resting stage, like a chrysalis or a tadpole stage, that's metamorphosis. If the baby already looks like a mini version of its parents, that's direct development.

**Recap.** Insects and amphibians transform completely through metamorphosis, while mammals and birds grow through direct development, staying the same basic shape the whole time.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Life Cycles of Organisms](https://lightmysky.com/learn/science/life-cycles-of-organisms-mt_4IVWRAZoNC)
- [Grouping Living Things](https://lightmysky.com/learn/science/grouping-living-things-mt_AylKwhbDWM)
- [Types of Metamorphosis](https://lightmysky.com/learn/science/types-of-metamorphosis-mt_ShAptVcQR3)

## Opens up

- [Plant & Animal Reproduction](https://lightmysky.com/learn/science/plant-and-animal-reproduction-mt_yNWt3GQBNp)