If you have ever been near the sea and walked along the shore where there are piers, rocks, and breakwater walls, then you’ve almost certainly seen barnacles. In fact, the “crust” you saw that was formed on the piers and rocks was made up of millions and millions of barnacles!

A barnacle is simply a small shellfish. When barnacles are hatched, they swim about freely. But when they reach adult state, they no longer move about. They attach themselves to any convenient surface and actually lose their power of locomotion.