We all know that hermit crabs carry shells that act as homes to them. If they outgrow the shell they will quite simply find a bigger shell to call home. The creatures mentioned above a virtually harmless to humans. Don't believe for one moment that all the creatures of the reef are harmless. The reef is home to very venomous snakes.
Sea snakes are ten times more deadly than a cobra.
One bite and you are pretty much a goner. In layman terms that means that you will die. If you are careful you can also hold the snakes in your hands. This is only for the foolhardy and brave individuals. One of my personal favorite creatures of the reef also make it there home.