These kids do love doing a science experiment. I wish I knew enough about science to explain some of the principles behind the things we do. A week or so ago we made the divers out of straws and clay. Then we put them in a two liter bottle filled with warm water. When you squeeze the bottle, the diver sinks to the bottom. Huge hit.
Decorating their bottles when we were finished – all kinds of fish and seaweed and mermaids appeared :-).