Greedy killer monkeys were found to be catching and gobbling up large rats in Malaysia. Shocked scientists uncovered the rat-catching macaques on palm oil plantations – and say the hungry predators could be used as pest control. The southern pig-tailed macaques were typically thought to chow down on fruit. They would also hunt for meaty prey sometimes, but generally only small lizards and birds. Now scientists have confirmed that these monkeys are also regularly snatching and devouring large rats.