"We repeatedly observed soft-sediment dwelling octopuses carrying around coconut shell halves, assembling them as a shelter only when needed. Whilst being carried, the shells offer no protection and place a requirement on the carrier to use a novel and cumbersome form of locomotion — 'stilt-walking'.
To date, invertebrates have generally been regarded as lacking the cognitive abilities to engage in such sophisticated behaviors.
The discovery of this octopus tiptoeing across the sea ﬂoor with its prized coconut shells suggests that even marine invertebrates engage in behaviors that we once thought the preserve of humans."
They didn't just crawl under the shells, they carried them around! That "stilt-walking" is fantastic. From an engineering point of view, it appears to be a lot of load per tentacle. Although it is underwater. Still, I can't imagine walking across the room on the tips of my fingers and toes. That coconut shell must be precious.