In this activity ecological understanding starts with recognising the differences between natural, biodegradable materials and non-biodegradable made materials. This basic understanding underpins the concepts of recycle, reuse and reduce that even the youngest children can begin to explore. The current ecological crisis has been caused by linear thinking, by people not recognising that we live in systems that are all connected and all feedback to each other. The problem with plastic, for example, is that we haven’t taken account of plastics’ non-biodegradability. Natural systems cannot absorb it. If we understood ecology, we would know that is a serious problem. This activity introduces these fundamental concepts to young children.