Preschool Germ Activity - Lesson Plan

I found a very interesting and fun way to teach preschoolers about germs. I have used it in 4 different preschool classes (ages 3-5) and even the very young children were able to understand and grasp the concept.  This is an inquiry-based experiment where the children discover and explain what has happened with the pretend germs.  It is great to use near the beginning of the school year to help children remember to wash their hands.  I just thought I would share it with you:

Preschool Germ Activity Lesson Plan

Number of Children:  Small Group 5-6 children

Purpose:   This experiment is meant to give children a visual representation of germs and allow them to discover how germs get transferred to objects from our hands and back to our hands.

Discussion will allow children to discover that germs can make us sick and that is why we need to wash our hands often.


1. Discuss what germs are and that they are on our hands even though we can’t see them.  Germs can make us sick.  

2. Tell the children to pretend that flour is germs.  Children will coat their hands in flour and then play with large legos for a few minutes on the table.

3. Children will then wash their hands with warm water and soap, come back and play with the legos again, and see that the flour (germs) transfers back to their hands.

4. We will discuss about what just happened – even though we washed our hands, the germs from the legos got back on our hands.  We will continue to discuss that these germs can make us sick and that is why we need to wash our hands often. 

Lesson Plan adapted from :