Many people visit Living History Farms to see our farm animals. We have sheep and pigs and chickens and cows and horses and…leeches. That’s right! The Schafer Drug Store in our 1875 town of Walnut Hill displays a bowl of leeches every summer.
What’s a leech? Well, have you have ever gone swimming in a lake or a pond and noticed you had a worm like creature attached to you when you got out of the water? EEEK! That was probably a leech. In fact, it was probably the North American Freshwater Medicinal Leech. Leeches are a type of worm; they don’t have bones the way you do and can stretch their bodies to be thin or squish themselves up really fat. They are usually brown or greenish with dark spots. Leeches can grow to be up to 2 inches long and have suckers on both ends of their body. Leeches are really wiggly! They can swim very quickly or crawl like an earthworm along the bottom of a lake using their suckers. Leeches do have eyes, but also use vibrations in the water to sense what is going on around them.
Leeches are parasitic. Parasitic means they need to feed on another living thing to survive. In the case of the Freshwater Leech, they survive on blood. These types of leeches are sometimes called bloodsuckers! The mouth sucker is filled with very sharp tiny teeth. It bites onto a living thing and sucks blood from them. When a leech bites onto something, it gives off a chemical in its saliva (its spit) that helps to keep blood flowing and also that keeps the victim from feeling any pain. Usually, leeches in the wild like to attach to fish, frogs, and turtles.
So why are there leeches in the Schafer Drug Store? Before people really understood the things that could make them sick (like germs!), people thought bad blood inside you made you sick. They thought you might have a poison in your blood or even that your body had too much blood! They thought a good way to make you well was to remove bad blood with…you guessed it, a leech! A long time ago, doctors would attach one, or even a bunch at a time, to the patient’s skin to suck out their bad blood.
What do you think? Do you think it would help make a sick person feel better? Now, we have a much better idea of why people get sick. Instead of bad blood, we know we might have bacteria or germs in our bodies that make us sick. We take special medicines to help get rid of the germs instead. Do you think it hurt to be bitten by a leech? Well, remember that chemical in the leech’s spit? It helps to keep people from feeling any pain. Most people do not feel it at all if a leech bites them.
Try this at home:
A single leech can eat up to ½ ounce of blood at a time. That is about 1 tablespoon. An adult human has around 160 ounces of blood in their body, so taking a half ounce out isn’t much.
What does a tablespoon look like? Ask your parents if you can measure out some water with a tablespoon sized measuring spoon. You can place water in a bowl and try measuring a tablespoon at a time into a second bowl. One tablespoon of water is how much blood one leech might eat. Sometimes, a long time ago, a doctor would use many leeches to remove “bad” or “poisoned” blood. One leech therapy called for TWO DOZEN leeches! That’s 24 leeches at a time! Measure out 24 tablespoons of water. Does that look like a lot?
DON’T FORGET: Visit the Schafer’s Drug Store at Living History Farms…the leeches have arrived! You can see what a leech looks like in real life and hear more about their story. Ask the interpreter in the Drug Store about ways doctors use leeches in 2014!
Tip for Caregivers: Leeches like cool weather. The leeches in our bowl are usually much more active in the mornings before it gets hot. When you visit the Drug Store, check out the leeches early in the day!