Weird Nature
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12 Bizarre Facts Most People Don't Know About Bloodsucking Leeches

Updated September 23, 2021 5.7k views12 items

Pretty much everyone in the world is familiar with leeches. These segmented worms have developed something of a sinister reputation over the years, due to the fact that these bloodsucking creatures were used in bloodletting procedures during the Middle Ages. Then add the image of people going into lakes and coming out covered in leeches, and you've got enough material to cause nightmares. 

While it isn’t exactly an undeserved reputation, as no one likes the idea of another living thing sucking on their blood, leeches are relatively harmless. They are also far more interesting organisms than just being tiny vampire worms. Whether it is the use of medicinal leeches in modern times or the fascinating life cycles that they have, you'll find that there are plenty of remarkable leech facts to discover in the list below.

  • All Leeches Are Hermaphrodites

    All species of leech are hermaphrodites, meaning that they have both female and male reproductive organs. They still require another leech to reproduce and have a rather unique way of fertilizing a partner. The leeches will line up alongside each other and then inject sperm sacks into each other. This allows the sperm to make its way to the female sexual organs, where it can find the eggs.

  • Leeches Have 32 Brains

    Photo: Manuel Krueger-Krusche / Wikimedia Commons / CC-BY-SA 3.0

    Leeches have 32 different internal compartments, each with their own brain. To be clear, the 32 brains are segments of a single brain, spread throughout the body. They are separate ganglia that have independent control over its respective segment. 

  • The Tyrant Leech King Has A Taste For Human Orifices

    Photo: Anna J. Phillips, et al. / Wikimedia Commons / CC BY 2.5

    The tyrant leech king has only recently been discovered in the Amazon of Peru. It is fairly large for a leech, reaching sizes of up to three inches. It has teeth that are five times bigger than any other member of the species. Unfortunately for those who encounter it, is has a habit of making its way into the orifices of a human body. Unlike other leeches that are happy to feed on areas like the toes and neck of their prey, the tyrant king focuses on the eyes, urethras, rectums, and vaginas. 

  • Some People Use Leeches In Beauty Therapies

    Some rather creepy beauty treatments are using leeches to help those who want better looking skin. In the procedure, leeches are applied to the body and allowed to suck out blood. The therapist then removes this blood from the worm-like creatures and mixes it with other materials. The resulting mixture can then be turned into a mask and spread onto a person’s face. Various celebrities have admitted to having the procedure done, which can apparently brighten and tighten the skin to give it a more youthful appearance.