The monkey has classically been known as the troublemaker in many cultures. As access to monkeys is limited for many people, most people won’t know how true this is.
Bali is filled with monkeys just waiting for gullible tourists to come along. Grabbing sunglasses off of heads, taking a child’s toy, grasping for plastic water bottles, and stealing any food in the vicinity is a common sight to see. This will be true anywhere, but in the Ubud Monkey Forest, the monkeys are safer to visit.