Most kids think a brain is a brain. Then they learn about octopuses.
Octopus: 9 brains
One central brain plus one mini-brain in each of its eight arms. Each arm can "think" independently — find food, react, even problem-solve — while the central brain does something else.
Octopus: 3 hearts, blue blood
Two hearts for the gills, one for the body. Their blood is blue because it uses copper, not iron, to carry oxygen. Works better in cold water.
Elephant: the memory real deal
An elephant's brain is huge (5 kg). Elephants recognise themselves in mirrors, remember migration routes across generations, and mourn their dead.
Bird: maps on the fly
A pigeon's brain has a GPS system tuned to Earth's magnetic field. A homing pigeon dropped 1,000 km from home will find the loft.
Ant: brain per gram
An ant's brain is tiny, but relative to body weight, it's one of the biggest in the animal kingdom. Individually dumb; collectively terrifying.
Dolphin: half-sleep
Dolphins sleep with half their brain at a time. The other half keeps them surfacing to breathe.
Human: the odd one
Our brain is 2% of our body weight but uses 20% of our calories. We're built around it. Most other species are not.