The title of this article begs the question, "When should we be teaching science to our children?"
Even before birth human beings may recognize natural phenomena such as pressure and temperature differences, and spontaneously react to changes in such things. These are learning experiences. It can be argued that as the brain continues to grow and develop, connections are beginning to be formed and subconscious memories created. Information gathered through the senses may be stored in unarticulated patterns in the brain. Here is the foundation for a scientific understanding of nature.
Dagenais, Raymond J. 2006. When is it Time for Science? Spectrum, 31(3), 14,15.