It is a remarkable discovery. It seems that octopus/octopi have the cognitive ability to use items in their environment in a creative way for their own protection:
“Australian scientists have discovered an octopus in Indonesia that collects coconut shells for shelter — unusually sophisticated behavior that the researchers believe is the first evidence of tool use in an invertebrate animal.
The scientists filmed the veined octopus, Amphioctopus marginatus, selecting halved coconut shells from the sea floor, emptying them out, carrying them under their bodies up to 65 feet (20 meters), and assembling two shells together to make a spherical hiding spot.”
This seems to be evidence of planning and preparation. The veined octopus is not having a “random walk” on the ocean floor. There is a level of cognitive processing – thinking – happening.