How to make a sugar snake

The MEL Chemistry boxes let you experiment with simple chemical reactions.
The sets are meant to excite children about chemistry.
Using a pile of sugar and baking soda, children can create a burning sugar snake.
Having mixed baking soda (NaHCO3 ) and sugar to a ratio of 4:1, the powder can then be set alight using solid fuel.
The snake starts to grow and, in some cases, can get up to 50cm long.