FILE – In this Jan. 24, 2015, file photo, Hindu holy men, perform a ritual by burning dried cow dung cakes in earthen pots at Sangam, confluence of rivers Ganges, Yamuna, and mythical Saraswati, at the annual traditional fair of Magh Mela in Allahabad, India. In India, where Hindus have long worshipped cows as sacred, cow dung has been used for centuries as fuel for fires – whether for heat, cooking or in Hindu ritual fires, where it’s a necessity. Now, online vendors like Amazon, ShopClues and eBay are selling cow dung patties to India’s ever-increasing urban population, especially those who grew up in villages. (AP Photo/Rajesh Kumar Singh, File)