I was in the monkey forest in Ubud with my clients from Denmark. They enjoyed their stay there. Besides the monkeys, they enjoyed the walk around the forests.
There are about six hundred monkeys who will entertain you once you get in the forest. It is not a forest like you may think a forest where it is hard to walk around. Since there are many visitors coming to this forest, the local government has made path around the forest.
These are the "polite monkeys", they don't snatch your glasses, earring, hair clip, or your credit card.
They have enough to eat so that they don't have to take your belongings and force you to buy food to exhange with stolen items. They don't have that kind of mentality.
Local provide them with sweet potato to feed them for several times a day. Of course, they will not refuse banana. Monkey and banana are just not to be separated. Close your eyes and say monkey to yourself, and your brain will think banana.
Please don't give your biscuit, coke, and peanut to them. It's not healthy for them. They can get sick. Especially the coke, they contain lots of sugar and who knows what's in the coke. It tastes nice, monkeys like it, but it is harmful for them.
You can buy banana at the entrance of the monkey forest. Small bunch wich consist of four bananas, cost about rp 20,000 and big bunch cost 50,000 rp. Bringing a bunch of banana to the monkey forest will attract the six hundred macaques. And that's not fun. So, hide them in your bag, but don't let the monkeys see you as you put them in your bag. And feed them one banana at the time.
When you feed the small monkey (ow, so cute!) the big monkey will come. The small monkey will run away. Okay, you probably think that you need to teach valuable lesson the big monkey how important is to share. But, please, don't. The rule of the jungle applies here.
Forget about talking to the monkeys, they won't talk to you back. You know why? Because their moms told them not to talk to strangers.