Does everyone have red blood?

Have you ever watched someone give blood? It’s an important job – blood only does a patient any good if the cells are still alive. That means that when you donate blood, you’re giving a part of yourself that’s still alive to somebody else! So what makes up the living soup called blood?

Most of it is red blood cells that carry things to your cells – that’s what gives blood its colour. There are so many red blood cells that in one single drop of blood, you could count over 5 million cells! Your blood is also full of superhero cells called white blood cells. These cells are like superheroes that patrol your body and make sure it’s safe. If anything that doesn’t belong there gets into your body, like an illness, these cells seek it out and destroy it!

So what happens if an animal doesn’t have red blood cells? They get a different colour of blood! Have you ever seen animals like crayfish or horseshoe crab that have shells on the outside of their bodies? Many of them have blue blood! That’s because they have different cells to carry oxygen around their bodies.

Some insects can also have different colours of blood depending on the food they eat. Their blood may be clear, yellow, or even green!