This is a video of a southern sand octopus shooting jets of water out of its
ass funnel to create quicksand so it can burrow into the sediment and hide from predators during the day. After digging its burrow, it lines the hole with a layer of mucus so it keeps its form while the octopus naps or whatever the hell octopuses do while they're sitting in a hole at the bottom of the ocean all day long.
A skilled architect, the octopus can build a mucus-lined home - complete with a chimney -20 centimetres down into the seabed, where it holes up during the day. It only emerges from its underground burrow at night to crawl over the seafloor and snack on small crustaceans.
Wow -- hanging out at home all day and only leaving to have a crab feast at night? That sounds like my dream world. Why couldn't I have been born an octopus? "You were destined to be an @$$hole." It's true, there is never a time during the day when someone isn't flicking me off for something I just did.
Keep going for a pictorial explanation, and the video.
Thanks to Shannon I, who built her home out of reinforced concrete like the fourth little pig you never hear about because he was rich and changed his name so he wouldn't be associated with those other three peasant pigs.