We had a great time studying digestion and the food chain one week. The next we studied chemical change and got to try it out ourselves with a baking soda solution mixed with berry juice from blackberries. The invisible baking soda mixture turns blue! Pro-tip for trying this at home: Smash the berries first and then paint it onto the baking soda writing instead of rubbing the berry straight onto the page. Also, use four tablespoons of baking soda for an 8 oz. cup of water to form the baking soda solution and let it dry for 10 minutes before painting it with the berry juice. We also enjoyed having some of the kids from the Axolotl Clan Studio come in to help us with our projects!