Lopburi's monkeys, which have a total lack of fear for humans, means they exhibit extremely bold behaviour, clambering across the windshields of moving vehicles and jumping all over bystanders in the street. Locals say there are even rival gangs that mark their territory - resulting in clashes when the animals meet. Government officials have tried to control the wild monkey population in recent years but have been unable to curb the numbers as the animals continue to multiply.