The 4-year-old Tonkean macaque exhibited prolonged attachment to the infant's desiccated corpse before starting to chew its remains.
More than 100 officers from the army and the police were deployed on Thursday as part of a week-long operation against mischievous macaques.
Sumatran orangutans remain critically endangered, but their numbers are higher than thought.
It just goes to show: You can't have it all.
Biodefense research used thousands of monkeys for painful experiments after 9/11.