From New Scientist:
Octopuses have been observed carrying coconut shells in what researchers claim is the first recorded example of tool use in invertebrates.
There is a growing record of tool use in animals and birds, from musical "instruments" made by orang-utansMovie Camera to sponges used by dolphins to dislodge prey from sand.
Now veined octopuses, Amphioctopus marginatus, have been filmed picking up coconut halves from the seabed to use as hiding places when they feel threatened.
"This octopus behaviour was totally unexpected," says Julian Finn, a marine biologist at Museum Victoria in Melbourne, Australia, who has filmed at least four individual veined octopuses performing the trick off the coast of Indonesia.