What is feux follet?

Feux follet is a French term which translates to "will-o'-the-wisp" in English. It refers to a natural phenomenon wherein small, flickering lights are seen in the dark, often over marshy or swampy areas. These lights are believed to be caused by the spontaneous combustion of gases emitted by decaying organic matter, such as plant material or methane released by decomposing animals.

The lights of feux follet are often described as blue or green, and may appear to dance or move unpredictably. In folklore, they are said to be mischievous spirits or witches who lure unwary travelers into dangerous terrain. However, the scientific explanation for feux follet suggests that they are simply a natural phenomenon, with no supernatural or malevolent properties.

Feux follet have been observed in many parts of the world, including Europe, Africa, Asia, and North and South America. They have been described in various ways, including fairy lights, jack-o'-lanterns, and corpse candles. Despite their mysterious appearance, feux follet are now generally understood as a natural occurrence and do not pose any danger to humans.