(CNN)Monkeys in Malaysia have been found to eat rats in such great quantities they could replace chemical pest control on palm oil plantations.
Pig-tailed macaques are widely regarded as pests themselves and researchers thought they mainly ate fruit, as well as small birds and lizards, according to a report published in Current Biology on Monday.
"I was stunned when I first observed that macaques feed on rats in plantations," said study co-author Nadine Ruppert, of Universiti Sains Malaysia, in a statement.
"I did not expect them to hunt these relatively large rodents or that they would even eat so much meat."
Palm oil has been much maligned for its role in driving deforestation, and researchers believe macaques could enhance palm oil sustainability by reducing rat populations.