Pianoro
Monte delle Formiche (Mount of the Ants) is situated between the valleys of the Idice and Zena rivers, about 30 km south of Bologna, and is the highest peak within the municipal territory (638 m s.l.m.).
Its name derives from a very particular phenomenon: every year, since the remotest times, swarms of male winged ants of the variety Mirmyca Scabrinodis have migrated to this summit in the early days of September to complete their nuptial flight. After mating, hundreds of thousands of ants go to die in the area of the sanctuary. It is a truly unique spectacle: you can see black clouds of ants descending from the sky to die all together. It is stil not clear from a scientific standpoint why this happens; it is perhaps because of this veil of mystery that over the centuries the phenomenon has come to be associated in popular tradition with the 8th of September, the Nativity of the Blessed Virgin Mary, though in reality the exact day can vary based above all on climate conditions.