The geography cone (Conus geographus) is a tropical sea snail that hunts fish. When a prey fish swims past, it will release a cloud of specialised insulin that induces a plunge in blood sugar level. The fish then experiences hypoglycaemic shock and becomes sluggish, making it easy to capture. Other cone snail species can also fire a harpoon-like proboscis. This has led to at least 30 human deaths while trying to collect their exquisite shells.