India, Aug. 19 -- On a recent evening at the dargah of Hazrat Nizamuddin Auliya, the qawwal singers were surrounded by a packed audience. Each member of the audience was a human, save for one. She had a tail, and she was seated in the best place, directly in front of the qawwals-see photo. Over the next hour, the qawwals continued with their qawwalis. The human audience swayed their head in sync with the mood of the qawwali's music and its devotional lyrics. But this cat didn't stir.

The 14th century sufi shrine in central Delhi is full of cats-about 150 cats, according to Jehangir Husain, a caretaker of the pilgrims' footwear. During the day, he says, the cats stay in their high-altitude hideouts in and around the shrine's domes and roo...