He would say no, that he had fallen, or that his shirt had got caught on the fence. It took me over a month to find out that an older boy was following him home from school and physically hurting him. There are many reasons why most children are afraid to tell their parents and get them involved. Either they internalize the names they are being called or feel like they should be able to handle it themselves. Other factors may include the way they feel their parents will react.
Every parent responds differently.
Janet dealt with her son's bully in a creative way. Paul and I had been having fun making fancy sub sandwiches, so the bully was getting a real treat. After two weeks, Paul confessed to me that he hadn't been able to eat his lunch for some time. He never approached Paul again. Paula did not get rid of her son's bully as easily.