As humans, our skeleton is really important for our survival! It's what keeps us upright and allows us to move.
But animals that don't have any bones at all instead have a protective outer layer a bit like armour. It's called an exoskeleton.
As well as supporting and protecting the animal, it also acts as a watertight barrier that stops the creature from drying out. It can also create a layer of toxins or chemicals on the outside of its exoskeleton to scare off predators.
However, unlike our bones which grow as we get bigger, an exoskeleton cannot change size or shape. This means that when an animal has outgrown its exoskeleton, it sheds it to make room for a new one!
Have a look at the images below to see some of the animals who have exoskeletons instead of bones!
