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Leeches

By Rebecca Hernandez

A medicinal leech does his business
Blood, blood, glorious blood.

You’ve probably heard that leeches can be used to help in certain medical practices, but unfortunately in nature they are still a pain in the butt. They are, after all, blood suckers.

A leech attaches itself to a host by using its anterior sucker which usually contains about a hundred tiny teeth. It is also equipped with quite a few other clever tools to do its job properly. Not only does it release an anaesthetic-like compound to numb the area that it is sucking, but it releases an anticoagulant to prevent the blood from clotting up.

Whilst these qualities do make the leech capable of being quite helpful during a medical procedure like limb reattachment (for which it is still used today), for a normal human who happens to not need any anti-clotting factor, the leech is quite a nuisance.

Leeches stay on your skin until they are full with blood, about 20 minutes, at which point they simply fall off. And that anti-coagulant? Well it keeps your wound bleeding quite a while longer than normal.

If you really have to get the leech off before it’s had its fill, be careful not to make the guy vomit up his dinner - the regurgitated blood might contain a disease that the leech is carrying which will so straight into your wound. Lovely!

Interesting fact: In the 19th century George Merryweather invented a device which used leeches to predict the likelihood of storms.

Danger of death: Leech bites won’t kill you but they do have the capability of passing diseases such as AIDS and Hepatitis B between people.

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10 Feb 2009
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