Octopuses, the eight tentacled cephalopods, have about 500 million neurons in their bodies. Most of the neurons are found in their arms, which allow the arms to problem solve on their own.
An octopus' arms can even react to stimulus after being cut from the rest of the body. The high concentration of neurons in an octopus' arms and the fact that the arms can function separately from the rest of the octopus have caused many to believe that the arms have a mind of their own. An arm can carry out instructions and resolve issues independently from the others. And even if an arm is cut off, it will continue to react to stimulus for some time.
More about octopuses:
- The oldest octopus fossil discovered is 296 million years old.
- Octopuses die soon after mating.
- Believed to have 8 arms for the longest time, experts have determined that octopuses actually use 2 of their tentacles as legs.