Each year, millions of monarch butterflies leave their northern ranges and fly south to the oyamel fir forests near the Sierra Madre mountains, where they gather in huge roosts to survive the winter. When spring arrives, the monarchs start their return journey north, with the population cycling through three to five generations to reach their destination.

Among the forest communities of central Mexico, monarchs are believed to be the souls of their ancestors. Monarchs carry the soul of a relative or friend who, for one night, returns to the world of the living. The “visit” is to celebrate Day of the Dead in the first days of November.