THE mother of identical quadruplet boys shaved numbers into her sons’ hair to help teachers and classmates tell them apart. Mum Tan Chaoyun, of Shenzen in China’s Guangdong Province, shaved the six-year-olds’ heads with the numbers one to four. She took the drastic step before they started elementary school because she was worried the boys would get mixed up. “My sons are identical, even to me,” said Tan who reckons the only difference between them is the shape of their eyelids.            –WO