The veined octopus (Amphioctopus marginatus), also known as the coconut octopus, has a skill beyond other cephalopods: it hides under animal and coconut shells, dragging them along the seafloor for protection. This is one of the few examples—if not the only example—of tool use in invertebrates. Here, the octopus sits inside a vacant bivalve shell. “This octopus displays tool-using behavior as it utilizes an empty shell for shelter and as a means of defense and protection," said Nature's Best photographer Jeffrey de Guzman. See more beautiful ocean photos in our slideshow of winners from the 2010 Nature's Best Ocean Views photo contest.