Activity overview

Run the activity

1. In pairs, discuss what might be a Plus, Minus and Interesting way to think about the question. Stuck for ideas? They could think about:

• Why it’s important for us to clean
• What kinds of microorganisms might they expect to find if no one cleaned
• Which areas of the house or school might have the most or least microorganisms
• What might happen to our health if we lived in these conditions

2. Ask the children to share their partner's ideas then encourage a broader discussion as a class, remember there is no wrong or right answer!

Background science

When asked this question your class might suggest that if the house or school was never cleaned then it would be full of germs. Really, they are talking about micro-organisms, which are very small living things that can’t be seen by the naked eye but are found all around us, even in the air we breathe. They’re also known as microbes or, more informally, germs or bugs.

The three types of microorganisms that your children need to know about are bacteria, viruses and fungi. Although some bacteria and viruses can cause illness in animals (including humans), not all microbes are harmful. Think about the yeast that makes bread rise or the bacteria used to make cheese and yogurt.

Take it further

Why not plan a survey of the school to work out where different microorganisms might be found? eBug from Public Health England have lots of resources and activities around microorganisms. This CIEC activity has the children investigating an irreversible change by making soap.
Take a look at some microorganisms that are out of this world with our extremophile What’s going on? and Zoom In, Zoom Out activities.

We have written this article on Microorganisms to help equip you with enough knowledge about them and how they affect us and our bodies, to be able to respond with confidence to any tricky questions that you may encounter.

Wellcome has also created an information hub about COVID-19 vaccines.