literally do = do exactly that It means: it is not an idiomatic expression. They really did crawl all over him. Well, almost.

It means that it really happened and that they really crawled all over them

"Literally" means something actually happened the way the writer described it to be. For example this writer wrote: "The boys literally crawled all over him..." This shows that the boys did the action of crawling on top of that one boy. You see when you describe an action to someone, it's usually simple, something like "The boys got on top of him and pulled his hair out." People don't usually use the word "Crawl". So this writer wants to tell you that these boys actually did the action of crawling on top of this boy.

Here it means 'really ,actually , in the sense of the word'. When something sounds far-fetched to really occur, like kids on their hands and knees crawling over the guy and pulling his hair, the word 'literally' is used to assure it is really happening and it is not a metaphor of any kind,but a real actual action.