During "mautâm", "Melocanna baccifera", a species of bamboo, flowers at one time across a wide area. This event is followed invariably by a plague of black rats in what is called a rat flood. This occurs as the rats multiply in response to the temporary windfall of seeds, and leave the forests to forage on stored grain when the bamboo seeds are exhausted, which in turn causes devastating famine. Famines thus caused have played a significant part in shaping the region's political history. The most recent spate of flowering, on the bamboo species' genetically linked timetable, began in May 2006, and the state government and the Indian Army attempted to prevent a famine.