India is planning to put its rising population of primates on the pill to tackle the growing "monkey menace" in its towns and cities, government wildlife officials have confirmed.
Vasectomies and sterilisation programmes are also being developed as part of a broader plan to curb the chaos being caused by troupes of marauding monkeys as urban India expands into their traditional forests.
Thousands of red-bottomed Rhesus Macaques or Bhandar monkeys are the scourge of New Delhi, where they roam through government buildings, chew Internet cables, bite the unwary carrying food and steal from people's homes.
Delhi's deputy mayor was killed when he was knocked from his balcony by clambering monkeys in 2007.
Until earlier this year, the Indian capital's employed "monkey catchers" deployed larger, black-faced Langur monkeys to scare away the macaques.
But since the use of and trade in Langur monkeys was banned earlier this year, the Indian government has been looking for a new solution.
Earlier this year officials from the Central Zoo Authority collaborated with the National Primate Centre in California to develop a new strategy with the Wildlife Institute of India. The researchers in California recommended a programme of oral contraceptives, female sterilisation and vasectomies, officials said.
Now Indian officials are exploring ways to administer the contraceptives and the likely impact of the drugs on primate behaviour before pressing ahead. One official said a mixed approach is likely to be adopted in Uttarakhand, in the Himalayan foothills where thousands of monkeys patrol the main roads and terrorise people in the hill towns.
Monkeys that can be caught will be sterilised while oral contraceptives will be put in food left for those primates that remain at large.
Professor P.C. Tyagi of the Wildlife Institute of India said he and his colleagues would move forward with the plans only when they are sure it will not have any harmful effect on the animals or their behaviour.
The need however is urgent, he said: "The population is increasing in the cities, they are causing a disturbance. People can't come out of their houses, they're taking clothes, biting people.
"One of the main advantages [of oral contraception] is that it is non-surgical. We'll look at how it works in other countries, carry out a trial, then we'll go ahead. If there are problems with the dosage, we'd need to work that out," he said.