Octopuses are among the most remarkable organisms on our planet; they have blue blood, three hearts, no bones, complex nervous systems, and a doughnut-shaped brain. They are well known for their high intelligence: they’ve been observed using tools, solving puzzles, and recognizing individuals outside their own species. There are about 300 known species of octopuses, and they lead generally solitary lives beneath the ocean’s surface. Ranging from less than an inch in length to the giant Pacific octopus, one of whom was discovered weighing 600 pounds and who spanned 30 feet from arm tip to arm tip, they are found throughout the world. All eight of their arms—on the underside of which are double rows of highly sensitive suckers—contain clusters of neurons that act as a mini brain to control movement, touch, and taste independently from the octopus’ central brain. This enables them to complete tasks with their arms more efficiently. Because of these two different, highly autonomous types of cognitive functions within a single organism, some researchers speculate that octopuses are not only self-aware, but might possess two levels of consciousness. Octopuses spend much of their time in dens, which can be a space under a rock, a burrow in the mud, an empty shell, or even a beer bottle. They are attracted to shiny objects such as seashells and rocks, and they have often been observed collecting and arranging these in their dens. They’ve even been seen using these objects to create little “gardens” in front of their dens. (The Beatles’ 1969 song “Octopus’s Garden” was written by Ringo Starr after learning about octopuses’ penchant for assembling such arrangement