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Sticker of Medicinal leech
Bug card No. 0901 of 1,500

Medicinal leech

Hirudo medicinalis
Eats: BloodSnails, slugs and wormsPonds, rivers and shoresNo legsNot an insect, but a bug cousin

The medicinal leech is a soft, stretchy worm that lives in muddy ponds. It is green or brown with a thin red stripe on its back. It has a sucker at each end, and for thousands of years doctors used it to take blood from sick people.

Fun fact: this one is not an insect at all, it has no legs! But kids find it on every bug hunt, so it lives in Bug Wiki too.
Lives in
Most of Europe and parts of Asia, in muddy, weedy ponds and ditches
Length
20 cm (7.9 in)
the biggest grown-ups
Top speed
about 0.04 km/h (0.02 mph)
On foot, estimate
Can it hurt you?
Can bite or sting
It can bite to drink blood, but the bite usually does not hurt because its spit numbs the skin. If one sticks to you, ask a grown-up to help take it off.
What does it eat?
It drinks the blood of animals, especially horses and other big animals that come to the water. After one big meal it can wait up to a year before eating again.
For real!Photo of Medicinal leech
Picture by Karl Ragnar Gjertsen Please credit Karl Ragnar Gjertsen This photo was taken by Karl Ragnar Gjertsen . Please credit this photo Karl Ragnar Gjertsen in the imme. CC BY 2.5, via Wikimedia Commons.

How big is it?

How long is it?

Medicinal leech about 20 cm long (7.9 in)A crayon about 9 cm (3.5 in)A banana about 18 cm (7.1 in)A house cat about 50 cm (20 in)
as long as 6 toy building bricks in a rowas long as 1 bananas end to endcould run across a dinner table in 90 seconds

How big is Medicinal leech compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

How fast is it?

cool stuff

Fun facts

1

It has three tiny jaws shaped like saws, with about 100 sharp little teeth on them.

2

Its bite leaves a funny mark: an upside-down Y inside a circle.

3

A big leech can drink up to ten times its own weight in blood in one meal.

4

Its spit has about 60 different helpers in it that keep blood runny while it drinks.

5

People in Ancient Egypt already used leeches as medicine about 3500 years ago.

you asked

Most asked questions about Medicinal leech

?Does a medicinal leech bite hurt?

Usually not. Its spit has something in it that numbs the skin, so most people hardly feel it.

?How big is a medicinal leech?

A fully grown one can stretch up to about 20 centimetres long.

?Are medicinal leeches still used by doctors?

Yes, leeches have been used in medicine for thousands of years. Today they are rare in nature and protected in most of Europe.

For bug experts

Scientific name
Hirudo medicinalis
Group
Snails, slugs and worms
Family
Hirudinidae
Classification
Clitellata > Arhynchobdellida > Hirudinidae
Lives on
Europe, Asia
Also known as
European medicinal leech

Where the facts come from

  1. Hirudo medicinalis (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by Karl Ragnar Gjertsen Please credit Karl Ragnar Gjertsen This photo was taken by Karl Ragnar Gjertsen . Please credit this photo Karl Ragnar Gjertsen in the imme. CC BY 2.5, Wikimedia Commons. The round sticker of this bug is cut from the same picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at hello@bugwiki.app and we will fix it.

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