The more we learn about the octopus  , the more intelligent we discover they are. Octopuses possess not one but nine "brains", one in each of their legs and a central brain behind the eyes. Octopuses can solve problems, can be trained to learn behavior and are extremely good at figuring out how to get out of an aquarium   and get into food. We can learn a lot from an octopus. An octopus doesn't have a backbone, which doesn't mean that they lack nerve. On the contrary, their nervous system, which goes all the way down each leg, is very complex. They are able to take in a lot of information about their world and seem to be able to remember, learn and adapt to new situations. The suckers   on their long legs can not only feel, but also taste. Each sucker works individually, so an octopus can just focus on one leg or one sucker. Their eyesight is sharp. Although their brains are quite small in comparison to ours, they still have very large brains for invertebrates  . They have many physical characteristics of a human brain. Perhaps you've seen the video of an octopus in a German aquarium that learned to open a jar to get its food. Octopuses have also been taught to go through mazes   and to pick out different shapes of patterns. Their short term and long term memory seems to be excellent. It is thought that octopuses are as intelligent as dogs in their capacity   to learn certain behavior, solve problems, and make use of objects. In the movie "Octopus Intelligence: Deep Sea Aliens," some species of octopuses are letting young octopuses watch the adults in order to train them. If this keeps up, in a hundred thousand generations the octopus may rule the seas. Clearly, there is more to an octopus than just a lot of legs. We can learn from the passage that the octopus   _  .
is the cleverest animal in the sea has nine small brains and a big one has a very complex nervous system has all its brains behind its eyes