Foxfire, also sometimes called "fairy fire", is the bioluminescence created by some species of fungi present in decaying wood. The bluish-green glow is attributed to luciferase, an oxidative enzyme, which emits light as it reacts with luciferin. It is widely believed that the light attracts insects to spread spores, or acts as a warning to hungry animals, like the bright colors exhibited by some poisonous or unpalatable animal species. Although generally very dim, in some cases foxfire is bright enough to read by.