Whale: The marine mammal that breathes with lungs

Although whales live in the sea and have "fish" in many of their names, they are not fish — they are mammals: animals that, like us humans, breathe with lungs and feed their babies milk. That fact often astonishes children hearing it for the first time. Let's meet them.

Its body

Whales breathe with lungs, so they cannot stay underwater like fish; they must surface now and then to breathe. When they exhale, a spray of mist shoots from the nostril on top of the head — the "blow" we often talk about. They also have a thick layer of fat, called blubber, wrapped around the body to keep them warm in icy seas. Their swimming is distinctive too: they move forward by sweeping the tail up and down, not side to side like a fish.

Its family and food

There are many kinds of whale: some have teeth and hunt fish and squid; others have no teeth and strain krill and small fish from the water through baleen. The largest animal on Earth, the blue whale, belongs to the whale family — it can grow over thirty metres long, longer than three buses end to end.

Its relationship with us

Whales are highly social; many species live in groups and stay in touch by calling. Some whale songs carry for great distances and are considered among the most complex sounds in the animal kingdom. Today, though, many whales are threatened by hunting, ship strikes and ocean pollution, and they need our protection.

A note for grown-ups

You could play a "guess whether it is a fish" game with a child, then find the reasons together: whales breathe with lungs and feed their babies milk — so they are mammals. Teaching a child to classify by features rather than memorise answers matters far more.