What your Preschooler will Learn from this Preschool Germ Activity:

- Germs on their hands by touching objects

- Germs on objects can be passed to other people

What you Need for this Preschool Germ Activity:

- Flour

- A washable toy for your preschooler to play with for ten minutes (plastic blocks or large legos are great)

- A washable spot that your preschooler will stay in for ten minutes with their toy (i.e.: the kitchen table)

What To Do:

Step one: Have your preschooler coat their hands with flour

Step two: Send your preschooler to play with the washable object

What will Happen During this Preschool Germ Activity?:

Every time your preschooler touches an object, they will get flour on it. Show your preschooler that when you pick up an object with flour on it, you get flour on your hands.

What to Teach your Preschooler During this Preschool Germ Activity:

- The flour simulates germs. Every time your preschooler has germs on their hands and touch something, the germs transfer to that object. And if you pick up that object with germs on it, the germs transfer to you.

- Teach your preschooler to wash their hands with warm soapy water to get rid of the germs and prevent spreading them to their favorite toys.

- While it may seem like a battle to get your child to cover their noses and mouths with anything when they cough or sneeze, preschoolers should be learning to cough and sneeze into a sleeve, shoulder or elbow to prevent germs from even getting onto their hands.

Variations:

If you really want your preschooler to learn from this preschool germ activity (and don't mind cleaning up afterwards), coat your preschooler's hands with flour and send them on their daily routine. They will coat everything they touch, such as doorknobs, toys, cups, books, toilet handles and chairs with flour. And they will learn that germs can and will live on everything they touch.

Hi! I'm Theresa Halvorsen, the preschool science and nature writer for Preschoolrock.com. I have twin boys and am blown away by their fascination with preschool science and how the world works around them. I am always looking for fun and simple science activities so preschoolers can learn about science and the natural world. Please contact me with any suggestions, ideas or questions you have about this site.

Helpful Tips for Parents

• Science fear is learned, not innate. Preschoolers approach science with natural confidence — protect that confidence by keeping science joyful and low-stakes.

• The best science projects are the ones children generate themselves by noticing something in the world and asking why. Adult-imposed experiments are valuable; child-generated experiments are extraordinary.

• Safety first: always supervise, taste-test nothing, wash hands after experiments. Model good safety habits — goggles, careful pouring, cleanup. Safety habits built in preschool persist.

• Always ask "What do you think will happen?" before running an experiment. Prediction is the core of scientific thinking, and preschoolers' predictions are always worth hearing.

Frequently Asked Questions

How do I keep science learning going between experiments?

Science is a mindset, not a schedule. Keep a magnifying glass accessible for impromptu investigation. Ask "why do you think...?" during daily life. Notice scientific phenomena out loud: "Look at how steam rises from the soup — where does it go?" Maintain a simple nature observation area (a window bird feeder, a terrarium, a weather chart). The child who develops the habit of curiosity about the physical world is doing science continuously, not just during scheduled experiments.

At what age can preschoolers do science experiments?

Simple science exploration begins in infancy — dropping objects (gravity), banging surfaces (acoustics), mouthing materials (texture and taste). By age 2, children engage meaningfully with water play, sand science, and simple mixing experiments. Between ages 3–5, children can follow simple experimental protocols: predict, observe, record, and discuss results. The scientific method — hypothesis, experiment, conclusion — is accessible at age 4 with appropriate support. The best preschool science is the child's own curiosity, not a formal curriculum.

Related reading: See also our color mixing science and our garden science guide for more ideas on this topic.

🎓 Skills Your Child Will Develop

• 📝 Recording & Documentation — Drawing what they observe, recording measurements, and noting results gives children their first experience of scientific documentation — and connects science to literacy and numeracy in an authentic context.
• 🔍 Observation Skills — Paying close attention to what happens during an experiment — noting colors, textures, movements, and changes — builds the observational precision that all scientific and analytical work requires.
• 🔬 Scientific Method — Even a simple experiment teaches the predict-test-observe cycle that is the foundation of scientific thinking — and preschoolers who internalize this process approach problems with genuine scientific confidence.
• ⚖️ Cause & Effect Understanding — Seeing that one action reliably produces a specific result builds the logical framework children use in mathematics, reading (one event causes another in stories), and everyday reasoning.

Since germs are invisible, your preschooler may not understand the importance of washing their hands to prevent the spread of germs. But with this fun preschool germ activity your preschooler can learn one way germs are spread. This preschool science experiment should teach your preschooler the importance of hand-washing, and using an arm or sleeve for coughs and sneezes.