How Octopuses Became the Ocean’s Smartest Invertebrates — 25 Problem-Solving Abilities

1. Tool Use: Coconut Shell Shelters

One of the most striking examples of octopus intelligence is their use of coconut shells as portable shelters. Researchers, including Julian Finn in 2009, observed veined octopuses collecting, carrying, and assembling coconut shell halves for protection on the seafloor.
This remarkable behavior shows planned tool use—a rare trait among invertebrates. By carrying the shells for future use rather than immediate benefit, octopuses reveal an impressive capacity for foresight and adaptability, challenging our assumptions about invertebrate cognition.