It started with a letter home. Over one week, each class in turn would have a morning devoted to science, and children were invited to bring one adult to share practical activities with them. The author, a granddad, got the job. In this article, granddad reflects on that morning's primary school science activity topic--camping. Granddad shares that as children grow up, they will see much in the media about waste of materials and energy, and will probably have to vote on policies concerning such matters. Everyone needs food, water, warmth, shelter, transport, medicine and so on, but he thought that this camping theme provided an excellent way of introducing the science behind some of the basic things one needs to conduct the life one takes for granted. (Contains 5 figures.)