Watch his eyes widen as he sees these creepy crawlies come to life! Measure 3 tbsp of baking soda into a beaker of warm water. Carefully cut gummy worms (Haribo Worms, 95p, groceries.asda. com) into three, lengthwise, and let your tot add them to the glass. Put aside for 15 minutes to allow the worms to soak up the baking soda. Then fish out the worms with a fork and add a couple at a time to a second beaker filled with white vinegar. Now stand back and watch them wriggle to the surface!