No matter how many rats the farmers of Mizoram kill, dump into piles and then set alight, it seems there are always more of the rodents to take their place.
In an unlikely cycle which takes place every 48 years, the north-east Indian state has been struck with food shortages and hardship after the flowering of a particular species of bamboo which provides an easy and ready source of food for rats.
The last time the bamboo flowered was in the winter of 1958-59. It did so again last year, triggering a plague of the rodents which has swept across the state.
The threat to crops and livelihoods has become so serious that the government of the mountainous, agriculturally dependent state declared an official disaster, increased rice rations and asked for federal assistance.
"We decided to increase the weekly allotment of rice to villagers so they will have enough to eat," said Tony Tawnluia, the state's Home minister. "We have ordered district officials to immediately increase wage rates and the grain supply."
The remarkable plant bringing misery and despair to Mizoram, sandwiched between Burma in the east and south and Bangladesh in the west, is muli bamboo (Melocanna baccifera) – which flowers only twice every century. The state is covered with bamboo forests and every time the muli flowers, rats feed on its seeds and their population soars. Some experts even believe the seeds increase the rats' fertility.
In the local Mizo language, the term for this cyclical phenomenon is mautam, and oral histories tell of mautam famines in both 1911 and 1862, when the flowering took place. In 1958-59, about 100 people starved to death as a result. Those deaths and the subsequent public anger also helped to fuel a 20-year war between Mizoram separatists and the federal government. The current state administration, headed by a former guerrilla leader, has been preparing for the next mautam for several years.
Early reports of the current mautam cycle came in late 2005. Rats destroyed crops in 60 villages in the east of the state last year and this year, the rat plague has steadily worsened. Experts at Mizoram's agriculture department estimated that up to 75 per cent of the annual rice harvest could be lost.
"Rodents are swarming across Mizoram, feasting on standing crops and leading to fears of a famine. The situation is indeed alarming," James Lalsiamliana, the state plant protection officer and head of its rodent control group, told the Associated Press news agency. "In a single night, the rodents can clip the ears from every rice stalk in a field."
To counter the threat, civilians are paid one rupee – about an eighth of a penny – for each rat they kill. Locals are required to bring the tails of the rats to the department to prove they have killed the pests and the tails are then burned by officials. At least 200,000 tails have been collected and destroyed. Meanwhile, scientists from Japan, Canada and Australia have travelled to Mizoram to study the growth of muli bamboo and assess its affect on the rat population.
Last year, rats destroyed the crops of more than 60 villages in the east of the state, where the bamboo first flowered.