Previously, I thought the most amusing use for empty coconut halves was emulating Monty Python and pretending that you are riding a horse. Now, it seems Indonesia’s Veined Octopus carries them around to use as an ad-hoc shelter. Apparently, this is the first unambiguous demonstration of tool use by an invertebrate. The behaviour is written up in the December 15th issue of Current Biology: “Defensive tool use in a coconut-carrying octopus:”
The fact that the shell is carried for future use rather than as part of a specific task differentiates this behaviour from other examples of object manipulation by octopuses, such as rocks being used to barricade lair entrances. Further evidence that this shell-carrying behaviour is an example of tool use comes from the requirement of the octopus to correctly assemble the separate parts (when transporting two shells) in order to create a single functioning tool.
Other significant talents of octopodes include colour shifting, escaping transparent boxes through tiny openings, using jellyfish tentacles as weapons, and having retinas the right way around, such that they have no blind spots.
Octopus intelligence has long been appreciated. For instance, Octopus vulgaris is the only invertebrate protected by the 1986 Animals (Scientific Procedures) Act (ASPA) in the UK.