Leeches might seem like relics of a bygone age of medicine, but they haven’t outlived their usefulness to people yet. The freshwater leech Helobdella austinensis can eat its weight in snails every day ...

For millions of people with diabetes, insulin is essential medicine. But for some ocean-dwelling predators, insulin is a weapon. With a burst of venom, a fish-hunting cone snail can drop the blood ...