2 slices white bread
2 resealable plastic bags, one labeled “dirty hands” and the other labeled “clean hands”
Instructions:1. At circle time, talk about how we all have germs on our hands.
2. Ask children to look at their hands and see if they can see any germs.
3. Explain that when the children come in from the playground, everyone needs to touch the bread in the bag labeled "dirty hands." Then put the piece of bread in the bag and leave it in the science center.
4. Next, have everyone wash their hands and touch the other piece of bread, then put it in the resealable plastic bag and leave it in the science center.
5. Observe over the next few weeks and compare the mold on both pieces.
6. Show children how to wash their hands and, if they are interested, repeat the experiment.