This is a well-documented, long-studied, instinctive behavior in primates (monkeys, apes, etc.) called the grooming response. Also well documented is that it usually is the females who are picking ...

Hiker's girlfriend Yi Ling Wang said: 'We we encountered a group of Formosan rock macaques grooming each other at the summit. 'As we paused to observe, a curious little monkey locked eyes with my ...