Life Cycle Wheels

Put each animal's life in the right order — then see why a butterfly's life is so much stranger than a hedgehog's.

Five animals, five ways of growing up.

Tap a stage, then tap the space it goes in

Words to know

Two completely different ways of growing up.

A butterfly and a frog go through metamorphosis: they change into something that looks nothing like what they were. A caterpillar essentially dissolves inside the chrysalis and rebuilds itself. A tadpole grows legs, loses its tail, and swaps gills for lungs.

A hedgehog, a parrot and a chameleon just get bigger. A hoglet already looks like a small hedgehog. This is called growing gradually — and it is what most animals, including you, actually do.

And notice what the hedgehog is missing. No egg. Hedgehogs are mammals, so the babies are born alive, and their mother feeds them milk. Every other animal on this page hatches.

Babies and their parents

Baby animals with their parents and the names for each

Kitten, puppy, duckling, lamb, calf, foal. Every baby animal has its own word, and learning them is proper vocabulary work dressed up as something lovely.

Note the elephant. A baby elephant is a calf — the same word as a baby cow. So is a baby whale, and a baby giraffe. One word, wildly different animals.

And our animals? A baby hedgehog is a hoglet. A baby galah is a chick. A baby chameleon is a hatchling. A baby tortoise is also a hatchling — because both of them come out of an egg, and that is what the word means.

Before and after

Egg → chick. Seed → plant. Caterpillar → butterfly. Tadpole → frog.

Look at how different two of these are. A chick still looks a bit like an egg-shaped bird; a seedling still looks like a small plant. But a caterpillar and a butterfly have almost nothing in common — different body, different legs, different food, different world. Same animal.

That is the difference between growing and metamorphosis, and it is worth stopping on. A child who really takes in that a caterpillar becomes a butterfly has understood something genuinely astonishing, and they should be allowed a moment to find it astonishing.

Small, medium, big

Growing sequences: puppy to dog, kitten to cat, chick to hen

Puppy → dog. Kitten → cat. Chick → hen. The same animal, just bigger. No dissolving, no rebuilding — this is growing gradually, and it is what you are doing too.

Line these up next to the caterpillar and the butterfly and the difference is obvious in a single glance. That is the whole lesson, and it does not need explaining.

One welfare point, since we are looking at puppies. A puppy is small for a very short time and a dog for fifteen years. The size of the animal you are buying is the size it will BE, not the size it is in the shop — and a golden retriever puppy that fits in your hands will end up needing two long walks a day for the rest of its life. That is not a reason not to have one. It is a reason to be honest with yourself first.