LEECHES are adapted by their structure and physiology to an ectoparasitic, blood-sucking mode of life. Some have secondarily become predators, but none has obvious adaptations to endoparasitism.

In this short film Dr Michael Mosley interviews a surgeon who is pioneering the use of leeches in medical research. He allows a leech to attach to his arm and suck his blood, the mouth of the ...

The leeches in both videos belong to a species called Chtonobdella fallax. The serendipitous nature of Fahmy’s encounters ...