Barnacles are crustaceans.
They are related to crabs.
Barnacles do not walk with legs, but they do eat and breathe with them! Their legs are called cirri, and they use them to sweep tiny food particles from the water and pass them into their mouth parts, inside of their protective plates.
Barnacles do not have gills. Their legs are feathery structures that can take in oxygen from the water.
Barnacles attach themselves to rocks, shells, ships, docks, whales, turtles, crabs and manatees.
A barnacle can be both male and female at the same time.
Barnacles do not have a heart or eyes.
Barnacles lay eggs.
Some people eat barnacles.