A word of caution on bouldering in Hampi. It goes without saying that bouldering is a risky sport. If you are a beginner try it only under proper guidance.
The Gray Langurs also called the Hanuman langurs that rules the boulder strewn landscape of Hampi.
It is not very rare to spot reptiles in the pits and shrubs around the boulder fields.
The langurs ruling the area can become your companions or enemies (if felt threatened) depend on how you treat them. There is no interspecies bouldering competition here. At the best borrow a couple of betas from them and leave them alone to their problems. That is going to be your effective strategy to deal with these master climbers.
Never try to tease or shoo them off. It's not going to work. They respond even to mild attention. Ganging up, hissing and grunting are typical signs of their agitation. Just ignore them and stop any provocation, they will simply disperse after some skeptical moments. You can go on with just another problem.
If still they are hanging around, see if someone is wearing a Tshirt with banana print on it!
While trekking off the trails, be on the lookout for the broken glass pieces (yep. beer bottles!) and those wicked thorny shrubs.
Do not venture alone into lonely places. Incidents of mugging is rare, but be prudent. Be careful with expensive things. Do not leave it unattended in the site.
For a larger list of general cautions in Hampi listed in the link. And of course you'll need to be sensitive to the local etiquette while in Hampi.