Hundreds of feet below the ocean’s surface, animals smaller than the palm of your hand make their houses out of snot. These bizarro creatures called larvaceans keep the oceans teeming with life by gobbling up anything nutritious that’s floated down from the surface.

These little guys, which are shaped like tadpoles, filter a truly shocking amount of water in a single hour — between two and four of those giant five-gallon water jugs that get delivered to your office, according to a study in the journal Science Advances. Giant larvaceans could push all of the water around them in Monterey Bay through their filters within 500 days; if a lot of them were all together and working as hard as they could, they could filter that same volume of water in just 13 days.

In order to find out exactly how these mysterious mucus-dwellers work, scientists at the Monterey Bay Aquarium Research Institute outfitted a remote-controlled vehicle with an arm wielding a laser to light up the food particles, and trained it on the giant larvaceans as they pumped water through their mucus and into their mouths. A video camera on the vehicle recorded the flow, and the scientists published their findings today in the journal Science Advances.

The nutrients that don’t go toward keeping these creatures alive and in luxurious mucus homes get pooped onto the seafloor. And if the snot houses get too clogged up, the larvaceans simply drop them. There, the poop and old mucus-shrouds feed bottom-dwelling sea creatures. It’s like a giant, oceanic, digestive system where nothing gets wasted — and where food gets grosser as it travels downward.