"Screaming Jelly Babies" (British English), also known as "Growling Gummy Bears" (American and Canadian English), is a classroom chemistry demonstration which is practiced in schools around the world. It is often used at open evenings to show the more engaging and entertaining aspects of science in secondary education settings.
The experiment shows the amount of energy there is in a piece of candy. Jelly babies or gummy bears are often used for theatrics. Potassium chlorate, a strong oxidising agent, rapidly oxidises the sugar in the candy causing it to burst into flames. The reaction produces a "screaming" sound as rapidly expanding gases are emitted from the test tube. The aroma of caramel is given off. Other carbohydrate or hydrocarbon containing substances can be dropped into test tubes of molten chlorate to produce similar results.
Net Reaction
4 KClO + CHO + 6 O  → 4 KCl + 12 CO + 11 HO