"It's called defensive defecation." Smelly Situation A pod of sperm whales reacted to being attacked by vicious orcas in relatable fashion: by shitting themselves violently. Observed by scientists on a tourist expedition off the southern coast of Western Australia, the distressed sperm whales — which are themselves fearsome predators , mind you — unleashed a "cloud of diarrhea" to deter the assailing orcas. The response wasn't necessarily out of fear. Rather, experts say it's a rare but effective defense mechanism. After letting loose a stinky slurry, the sperm whales used their tails to fan the poop cloud towards their attackers to confuse them. "It's called defensive defecation," Jennah Tucker, a marine biologist who witnessed the incident, told ABC . "And it seems like it actually did work in this case." Poop Propellers As shown in footage shared by Whale Watch Western Australia, the sperm whales stayed together in a tight circle, keeping their heads in the center and their tails pointed outwards. "This is called a rosette, another defensive mechanism they use when they're under attack," Tucker told ABC . The rosette is a powerful way of fending off attackers. As sperm whales boast an impressive average length of around 50 feet, their trashing tails are intimidating deterrents. But while their formation held strong, a "massive dark bubble" suddenly appeared. Then the orcas left. At first, the horrorstruck onlookers thought that the orcas had managed to kill a young sperm whale. Later, when the scientists reviewed the footage, they realized that the seeming blood in the water was really just excrement. An easy mistake to make, apparently. "Because sperm whales' diet consists mostly of squid, they actually have this really reddish coloured poo," Tucker added. Too Big to Fail Sperm whales are the largest predators in the world. For a while, Tucker explained, many believed that they were immune to being attacked. Yet what orcas lack in sheer size — and they're still pretty big, with the largest around 30 feet long — they make up for in brutal cunning, along with strength in numbers. They're clever and audacious enough to take out human vessels , and with enough of them in a pod, can overwhelm any prey. "There have been a few accounts now of successful predations on sperm whales, but it is extremely rare globally and historically," Tucker said. And if they keep crapping themselves like in this latest display, maybe they won't be preyed on by orcas at all. More on oceans: Coral Reefs Coaxed Back to Life by Playing Happy Reef Sounds on Underwater Speakers