Indian officials have enlisted the help of black-faced langur monkeys to provide security for the venues hosting the Commonwealth Games. Their purpose is to scare away smaller monkeys that have been harassing fans near arenas, the BBC reports. The aggressive langurs are kept on leashes by handlers but released when the other monkeys appear.
Monkeys are a serious nuisance in India, where they are a common sight on mass transportation and sports arenas. They've even showed up at parliament, the prime minister's office, and the defense ministry. Because they're considered sacred, authorities don't kill them.