Insects have their skeleton on the outside of their body. Their exoskeleton helps protect them, but they have to shed it and grow a new one when they get to big.
There are over 1 million different species of insect, and there is thought to be at least 6 million more species that haven’t been discovered yet.
For every single human alive, there are about 200 million insects. There are more insects in a square mile of countryside than there are human beings on the planet.