Who carries a home on their back?

Have you ever carried a backpack on your back? You can feel it bump gently as you walk. When you get home, you take it off.

Some animals carry something on their back too. For them, it is not a bag. It is their home! So who carries a home on their back?

The first one is the snail. A snail has a soft, wet body and a hard, curly shell on top. When a bird comes near, the snail pulls its body inside to stay safe.

A snail grows its shell from its own body. As the snail gets bigger, its shell grows bigger too, round and round. That is why a snail never has to move house.

A turtle carries a home on its back as well. Its shell grows as part of its body, joined to its bones. So a turtle can never climb out of it.

When a turtle feels scared, it tucks its head and legs inside. The hard shell keeps it safe, like a little house with the door shut.

Down by the sea lives one more animal with a home on its back. It is called a hermit crab, which is a little crab that lives in a borrowed shell.

A hermit crab has a soft back that needs keeping safe. So it finds an empty shell left behind by a sea snail. It climbs inside, and now that shell is its home.

But a hermit crab keeps growing, and its borrowed shell does not. One day, the shell feels too tight. What do you think the hermit crab does then?

It looks for a bigger empty shell! The hermit crab feels inside the new shell with its claws. That way it knows the shell is empty and roomy. Then it wriggles out of the old one and into the new one.

Let's remember our new word: hermit crab. Snails and turtles grow their own shell homes, and hermit crabs borrow theirs.

Sleep snug and safe tonight, just like a snail curled up in its cozy shell.