Another possibility is that they come from fireflies, of which three species are common in Japan: "Luciola cruciata" (, "Genji hotaru"; meaning „Genji´s firefly“), "Luciola lateralis" (, "Heike hotaru"; meaning "firefly from Heike"), and "Colophotia praeusta". All these snail-eating beetles and their larvae are famous for their ability to make special body parts glow (bioluminescence) and make them blink rhythmically. Every year at the Fusa-park in Tokyo the legendary feast "Hotarugari" (; meaning "firefly catching") is celebrated. They have also been thought to possibly be misrecognitions of shooting stars, animals that have luminous bryophytes attached to them, gasses that come from swamps, light bulbs, or visual hallucinations. There have also been some "artificial hitodama" created using combustible gases (an experiment in 1976 by the Meiji University professor, Masao Yamana using methane gas).