Occasionally mistaken as stars and common in the Land of Wind and Shade, fireflies have no real purpose so far.
These fireflies are stuck in the sky when the breeze stops flowing from the pipes on LOWAS. It was stated by an amphibious inhabitant that the fireflies are stuck because of a spell cast on them by The Slumbering One.
Furthermore, there are at least 4 fireflies in LOCAH as it is shown that the four lanterns that power the crypt mechanisms are These lanterns seem to be connected to the vital state of each the post-scratch kids. The reason why Dirk's lantern exploded and the fate of this particular firefly is unknown.