In Malaysia, wild pig-tailed macaques do not have the best reputation and are even considered a crop pest. Contrary to this, they actually feed on rats, the major oil palm pest, and can provide an important ecosystem service as biological pest control agent. This was found by a team of researchers from Universiti Sains Malaysia (USM), the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University (UL) and the Max Planck Institute for Evolutionary Anthropology (MPI-EVA). Their research investigates the costs and benefits of macaques foraging in oil palm plantations.