The geography cone (Conus geographus) is a tropical sea snail that hunts fish. When a prey 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 is left sluggish, leading to easy capture. Other cone snail species can also fire a harpoon-like proboscis. This has lead to at least 30 human deaths while trying to collect their exquisite shells.