Memory That Lasts

Octopuses form long-term memories that hold for months. Give the same individual a puzzle again weeks later and it remembers the trick.

Even more telling: hand the same puzzle to several octopuses and they do not all settle on one method. Each works out its own preferred solution and sticks with it. That mix of lasting memory and personal strategy is a far cry from the simple, fixed instincts we expect from an invertebrate.