---
title: "Whales & Dolphins Are Mammals"
description: "Know that whales and dolphins are mammals, not fish — they breathe air, are warm-blooded, and feed their babies milk — even though they live in the ocean"
canonical: https://lightmysky.com/learn/science/whales-and-dolphins-are-mammals-mt_mRCPP_Ab2W
source: https://lightmysky.com/learn/science/whales-and-dolphins-are-mammals-mt_mRCPP_Ab2W.md
retrieved: 2026-10-19
---

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# Whales & Dolphins Are Mammals

Know that whales and dolphins are mammals, not fish — they breathe air, are warm-blooded, and feed their babies milk — even though they live in the ocean

Subject: Science · Area: Ocean Life · Ages 5 to 7
Page: https://lightmysky.com/learn/science/whales-and-dolphins-are-mammals-mt_mRCPP_Ab2W

## Ready when they can

- State that whales and dolphins are mammals, not fish
- Give at least two reasons why: they breathe air and feed babies milk
- Explain that living in water does not make an animal a fish

## Lesson: Whales and Dolphins Are Mammals, Not Fish

Whales and dolphins live in the ocean. But they are not fish. They are mammals, just like you and me.

Mammals breathe air, just like you do. Whales and dolphins come up to breathe. Mammal babies drink milk from their mothers. Whale and dolphin babies do this too.

*(drawing: Two things make a mammal: breathing air and feeding milk to babies. Tap to count them.)*

**Example.** A baby dolphin swims next to its mom. It drinks her milk to grow big and strong. Every few minutes, it swims up for air.

**Tip.** Living in water does not make an animal a fish. Ask if it breathes air and drinks milk. That tells you it is a mammal.

**Recap.** Whales and dolphins breathe air and feed their babies milk. That makes them mammals, not fish.

## Practice

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

## Needs first

- [Ocean Animal Variety](https://lightmysky.com/learn/science/ocean-animal-variety-mt_ytUG3yjCYt)

## Opens up

- [Classifying Ocean Animals](https://lightmysky.com/learn/science/classifying-ocean-animals-mt__aHSZTm5k5)