This is pretty normal guinea pig behaviour, but if he is doing it a lot it could be because he is bored.
Does he have lots of things to play with in his cage?
Aside from lots of fresh hay he should also have things to chew on, places to hide, and some stuff to move around and play with.
This doesn't need to be expensive stuff - there are lots of things you can make yourself that he will love - empty toilet rolls stuffed with hay, cardboard boxes with holes cut in them, paper bags, etc.