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Fake Blood

In this activity, students make fake blood and discuss the importance of blood in our bodies.

Without blood, we'd be in trouble. Without blood, not only would be look like a wilted vegetable, we'd be unable to move gases like oxygen and carbon dioxide, and various nutrients around. Use this activity and the information below to start a discussion in your class about blood and what it does.

  • About 8% of our weight is blood (multiply your weight by 0.08, or 8%, to get the result). If you weigh about 50 kilos (110 pounds), you have the equivalent of two 2-L pop bottles of blood in your system.
  • Although most people become queasy at the sight of blood, it is the preferred meal for many animals, including lice, bedbugs, leeches, ticks and mosquitoes. Being a blood eater is a pretty great thing because almost every creature has blood. It's also very nutritious stuff! Blood contains lots of protein and protein is necessary for a balanced diet.
  • Humans eat blood, too. A number of cultures worldwide make blood sausages using various mixtures of congealed blood, animal fat, and grains. Blood sausage or 'black pudding' is particularly popular in parts of the UK, where it is a key part of a traditional breakfast! The Masai people of Africa are herders and who will sometimes make blood milkshakes by cutting a vein in the neck of a cow, (a healthy cow can lose up to 5 litres of blood without being harmed!) and mixing the collected blood with some milk. 


  • Describe the importance of blood.


  • Per Class or Demo:
    clear corn syrup
    red food colouring
    powdered cocoa
    small plastic baggies

Key Questions

  • What is the importance of blood in our body?
  • Why is blood a good food for animals?
  • Why do we get queasy at the sight of blood?

What To Do

  1. In a large plastic bag or mixing bowl, mix ¼ cup corn syrup and 2 tablespoons of water, thinning out the corn syrup to make it runny.
  2. Add 4 drops of red food colouring and mix well.
  3. Add 2 tablespoons of cornstarch, ½ tablespoon of powdered cocoa, and stir well. Add more food colouring if necessary, to achieve the desired effect.
  4. Spoon out the fake blood into small plastic baggies for students to play with and take home.
  5. Use the fake blood to start a discussion on the blood in our bodies.


  • Make your own fake blood recipe representing the four components of blood: red blood cells, white blood cells, plasma, and platelets. What is the role of those four components?

Other Resources

Science World Resources | Faux sang maison | French version of this resource