How Smart Is an Octopus?

Answer:

The octopus inhabits many diverse regions of the ocean, including coral reefs, pelagic waters, and the ocean floor. They have numerous strategies for defending themselves against predators, including the expulsion of ink, the use of camouflage and deimatic displays, their ability to jet quickly through the water, and their ability to hide. An octopus trails its eight arms behind it as it swims. All octopuses are venomous, but only one species, the blue-ringed octopuses are known to be deadly to humans.

A cold, diabolical intelligence is a quality that writers commonly attribute to the octopus and its tentacle kin. Octopuses, squid, and cuttlefish do indeed have large brains (they are the only mollusks that do), but their intelligence appears to be limited.

Of these big-brained animals, the octopus has been the most intensively studied. Octopuses have learned to negotiate mazes and to respond to such cues as colored lights and objects of different size and shape. On the other hand, they cannot figure out how to extract a crab — their favorite food — from an open-topped glass jar. Octopuses are highly curious, a trait that is usually linked to intelligence. In nature they sometimes build shelters out of loose rocks, which also implies a certain degree of intelligence. Though captured octopuses have an uncanny ability to escape from their containers, this is due not to reasoning but to their ability to make tentacles and body extraordinarily flat (almost as thin as a sheet of paper) and then ooze out through cracks.