Nearly indestructible, powerful venom with no cure, a huge swarm off Japan in 2005 and these things are acting as if sentient- upping their reproductive rate to counter the Japanese attempts to slaughter them. That's 20,000 to 30,000 babies at a go!
Far more than I'd imagined. They corral fish, then go in and get lunch? I really did think they were near passive creatures. And their lifecycle is amazing.
