Monkeys typically eat black grapes by using their hands to pick them from trees or vines. They will hold the grapes and nibble on them, often peeling off the skin with their teeth or popping them straight into their mouths. Some monkeys may also take a playful or curious approach, inspecting the grapes before eating them, and occasionally sharing them with other members of their troop. Their eating habits are similar to how humans eat grapes, but they might be more focused on eating quickly or in a group setting. Do you have a specific type of monkey in mind?