Blood comes up a lot in "Barn Burning" though usually in terms of the blood shared by relatives. At the beginning of the story Sarty smells something besides food in the store. He smells "the old fierce pull of blood" (2). Since this line is followed by the story's first mention of Abner, we realize that this pull Sarty is talking about is the blood bond he feels exists between him and his father. At this point Sarty seems to think this familial bond is important. But, something changes when his father tells him this: "You've got to learn to stick to your own blood or you ain't going to have any blood to stick to you" (29).
Abner is both threatening Sarty with abandonment and suggesting that Sarty is responsible for keeping his father alive. As we see in the barn-burning scene, Sarty's not sticking by his father's blood could threaten his father's life. Ultimately, and perhaps even in this moment, Sarty realizes that he doesn't want "to have any blood to stick to [him]." For Sarty this "old fierce pull of blood" symbolizes the one-sidedness of his father's idea of blood ties, and the relative ease with which these ties can be broken. Still, we know Sarty travels back in his memory to the moment discussed here twenty years later. Sarty is still tied by blood and by memory to his father.