Just a short walk from the ubud market is a jungle full of sly, clever, bullies. Don't be fooled by thier cute puppy eyes, and smaller proportions, zip your shit up, and lock everything down. I saw a monkey pull a bottle of water from a person, untwist the cap, pour the water onto the ground, then proceeded to drink with his homies. These monkey's open bags, rummage through your things, take loose articles of clothing, eat your lunch, then growl and show their fangs if you attempt to retrieve your stuff. Don't worry though, there are workers to help with stolen goods, but if it's food, consider that gone.
There are a lot of "LOL" moments as you hike through the forest. Beyond the monkey heist that leaves you in shock and awe. The Macaca fascicularis or Balinese long-tailed monkeys are majestic. If you stand back and observe, there is a sense of community. They are so human like, because they have a long history of living along side humans. They fight, mate, groom, and care for each other just like we do. Unlike what pop culture demands, these monkey's feed on sweet potatoes, not bananas. Although bananas are sold on location.
Fun fact: These monkeys are opportunistic, they've been documented to use tools to gather food. I saw this first hand. One monkey wrapped an acorn neatly inside a leaf, then carefully scraped the package back and fourth on a concrete slab, making sure he's not causing too much friction, thus damaging the nut. I've got a video, I'll make it into a gif.