It's the beginning of the spooky season, which means ghouls, ghosts, and bloodsuckers abound. One of the most famous bloodsuckers in nature is, of course, the leech. These parasites feed on blood and ...

You might think you know leeches: Go for a swim in the wrong shallow lake, and you’ll emerge covered in sleek black bloodsuckers that have decided you’re their next meal. But inside a leech, ...

European medicinal leeches were famous for their popular purpose: treatment for everything from cancer to mental illness. But the high demand left them endangered—still today. Bloodletting ...