* Vocalizations: Different types of calls and screams, each with a specific meaning.
* Body language: Posture, facial expressions, and gestures convey a lot of information.
* Scent marking: Some monkeys use urine or feces to mark their territory and communicate.
So, there's no one "Hello" equivalent in monkey communication.
However, if you're looking for a fun way to greet a monkey:
* You could try mimicking a friendly vocalization you've heard monkeys make.
* Offer them a treat (if it's safe and appropriate for the specific monkey).
* Make gentle, slow movements to avoid scaring them.
Remember, always be respectful of animals and their communication methods.