The Crustaceans That Act Like Glue

Barnacles are not mollusks despite their shell-like appearance. These creatures are actually crustaceans related to crabs and lobsters that spend their entire adult lives glued to a single rock.

After a brief swimming stage as larvae, barnacles permanently cement their heads to a surface. They secrete one of the most powerful natural adhesives known to science, which is so durable that researchers study it for medical use. Because they are stuck in place, they use their feathery legs to kick food directly into their mouths. It is quite a strange lifestyle for an animal that is essentially a sideways-swimming shrimp in disguise.