"In Many Things Under a Rock, marine biologist David Scheel investigates four major mysteries about these elusive beings. How can we study an animal with perfect camouflage and secretive habitats? How does a soft and boneless creature defeat sharks and eels, while thriving as a predator of the most heavily armored animals in the sea? How do octopus bodies work? And how does a solitary animal form friendships, entice mates, and outwit rivals? Over...