This is a simple experiment which delights young children from pre-K through grade 3 and is integrated with children's literature.
Children seem to prefer stories that they have never heard or stories that they know very well.
This is one that many children have not heard. Integration of a story with an activity allows the teacher to use class time more efficiently because language arts are being considered at the same time as science. A long time ago, we tell them, a Lenape Indian chief looked out and saw a crow in the sunlight. That story has been passed down from grandfather to grandson through many years, and is what we now call a legend. Pour about 5 cm of water into a plastic tennis ball container or tall glass.