Oobleck (Non-Newtonian fluid)- Large aluminum trays filled with Oobleck (cornstarch, water, food coloring), and plastic toy animals next to the trays. Kids can poke the Oobleck with their finger or with a plastic toy. They will not be able to penetrate the Oobleck as it will behave like solid. If they slowly insert their finger or toy into the Oobleck, their finger/toy will go in easily and behave like a liquid. They can make a ball of Oobleck and then let it flow between their fingers.