This is one of my favorite ukiyo-e (Japanese woodblock prints). It's by the great Hiroshige.
In Japanese folk beliefs, foxes (kitsune) are imbued with magical powers, among them the ability to change their physical form to trick silly humans into doing their bidding.
It was thought that on New Year's Eve, all the foxes in the provinces around Edo (modern Tokyo) would gather at the Oji Inari Shrine north of the city. The shrine was dedicated to Inari, the god of the harvest (and lots more). The foxes would meet at a tree near the shrine and change their dress into suitable shrine-visiting attire.
On their way to the shrine, they would give off kitsunebi (foxfire) by which farmers could predict the harvest for the coming year. And foxfire is real: We call it swamp gas; it's also caused by bioluminescent fungi.
But I like to think mischievous foxes are responsible.
This print is part of the Hiroshige series "One Hundred Famous Views of Edo" and was first published in 1857. I bought this modern reprint years ago in Kyoto.
Recent postings by my blog friends Robert Brady on Hiroshige and Tamar on a nocturnal encounter with foxes brought this print to mind.
Bob's and Tamar's postings made me wistful for a long-ago time before science had precise answers for nearly everything, when things we couldn't fully understand were given such evocative and creative explanations.
Let the foxfires burn.