Monkeys are funny, as well as dangerous.

I have already done asking a question about how should one go about camping where there are monkeys around: http://outdoors.stackexchange.com/q/10396/2303

The best advice would be to avoid them you are unsure about your own safety.

while number of Rock Climbing places in India are habitats for these monkeys, living in the natural caves, playing all day on the edges and cliffs, as a climber, I have always seen that when I am at the base of one such climb, as I approach they panic. 

Do other people in the rest of the world have had a similar issue?
What would you do if have climbed up a good way and then you find a gang of monkeys up over the wall? Wiser call to call it a day and retreat?